diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/Program.cs b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/Program.cs
new file mode 100644
index 000000000..7937a9ba0
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/Program.cs
@@ -0,0 +1,16 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+
+namespace TestApp
+{
+    public class Program
+    {
+        public static int Main(string[] args)
+        {
+            Console.WriteLine(TestLibrary.Helper.GetMessage());
+            return 0;
+        }
+    }
+}
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/TestApp.sln b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/TestApp.sln
new file mode 100644
index 000000000..0935de81a
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/TestApp.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "TestApp", "TestApp.xproj", "{0138CB8F-4AA9-4029-A21E-C07C30F425BA}"
+EndProject
+Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "TestLibrary", "..\TestLibrary\TestLibrary.csproj", "{DC0B35D0-8A36-4B52-8A11-B86739F055D2}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{0138CB8F-4AA9-4029-A21E-C07C30F425BA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0138CB8F-4AA9-4029-A21E-C07C30F425BA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0138CB8F-4AA9-4029-A21E-C07C30F425BA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0138CB8F-4AA9-4029-A21E-C07C30F425BA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{DC0B35D0-8A36-4B52-8A11-B86739F055D2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{DC0B35D0-8A36-4B52-8A11-B86739F055D2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{DC0B35D0-8A36-4B52-8A11-B86739F055D2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{DC0B35D0-8A36-4B52-8A11-B86739F055D2}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/TestApp.xproj b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/TestApp.xproj
new file mode 100644
index 000000000..d18702195
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/TestApp.xproj
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0.23107" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">14.0.23107</VisualStudioVersion>
+    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.Props" Condition="'$(VSToolsPath)' != ''" />
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>0138cb8f-4aa9-4029-a21e-c07c30f425ba</ProjectGuid>
+    <RootNamespace>TestAppWithContents</RootNamespace>
+    <BaseIntermediateOutputPath Condition="'$(BaseIntermediateOutputPath)'=='' ">..\..\..\artifacts\obj\$(MSBuildProjectName)</BaseIntermediateOutputPath>
+    <OutputPath Condition="'$(OutputPath)'=='' ">..\..\..\artifacts\</OutputPath>
+  </PropertyGroup>
+  <PropertyGroup>
+    <SchemaVersion>2.0</SchemaVersion>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.targets" Condition="'$(VSToolsPath)' != ''" />
+</Project>
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/project.json b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/project.json
new file mode 100644
index 000000000..666d644b9
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestApp/project.json
@@ -0,0 +1,30 @@
+{
+  "version": "1.0.0-*",
+  "buildOptions": {
+    "emitEntryPoint": true,
+    "preserveCompilationContext": true
+  },
+  "dependencies": {
+    "TestLibrary": {
+      "target": "project",
+      "version": "1.0.0-*"
+    },
+    "Microsoft.NETCore.App": "1.0.1"
+  },
+  "frameworks": {
+    "netcoreapp1.0": {}
+  },
+  "runtimes": {
+    "win7-x64": {},
+    "win7-x86": {},
+    "osx.10.10-x64": {},
+    "osx.10.11-x64": {},
+    "ubuntu.14.04-x64": {},
+    "ubuntu.16.04-x64": {},
+    "centos.7-x64": {},
+    "rhel.7.2-x64": {},
+    "debian.8-x64": {},
+    "fedora.23-x64": {},
+    "opensuse.13.2-x64": {}
+  }
+}
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/Helper.cs b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/Helper.cs
new file mode 100644
index 000000000..6c3bc0e53
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/Helper.cs
@@ -0,0 +1,15 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+
+namespace TestLibrary
+{
+    public static class Helper
+    {
+        public static string GetMessage()
+        {
+            return "This string came from the test library!";
+        }
+    }
+}
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/TestLibrary.csproj b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/TestLibrary.csproj
new file mode 100644
index 000000000..2debc348d
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/TestLibrary.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard1.5</TargetFramework>
+    <AssemblyName>TestLibrary</AssemblyName>
+    <PackageId>TestLibrary</PackageId>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NETStandard.Library" Version="1.6.0" />
+  </ItemGroup>
+
+</Project>
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/TestLibrary.xproj b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/TestLibrary.xproj
new file mode 100644
index 000000000..dc8eb7060
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/TestLibrary.xproj
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0.23107" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">14.0.23107</VisualStudioVersion>
+    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.Props" Condition="'$(VSToolsPath)' != ''" />
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>dc0b35d0-8a36-4b52-8a11-b86739f055d2</ProjectGuid>
+    <RootNamespace>TestAppWithContents</RootNamespace>
+    <BaseIntermediateOutputPath Condition="'$(BaseIntermediateOutputPath)'=='' ">..\..\..\artifacts\obj\$(MSBuildProjectName)</BaseIntermediateOutputPath>
+    <OutputPath Condition="'$(OutputPath)'=='' ">..\..\..\artifacts\</OutputPath>
+  </PropertyGroup>
+  <PropertyGroup>
+    <SchemaVersion>2.0</SchemaVersion>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.targets" Condition="'$(VSToolsPath)' != ''" />
+</Project>
diff --git a/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/project.json b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/project.json
new file mode 100644
index 000000000..032754312
--- /dev/null
+++ b/TestAssets/NonRestoredTestProjects/PJAppWithSlnAndOneAlreadyMigratedCsproj/TestLibrary/project.json
@@ -0,0 +1,9 @@
+{
+  "version": "1.0.0-*",
+  "dependencies": {
+    "NETStandard.Library": "1.6.0"
+  },
+  "frameworks": {
+    "netstandard1.5": {}
+  }
+}
diff --git a/src/dotnet/commands/dotnet-migrate/MigrateCommand.cs b/src/dotnet/commands/dotnet-migrate/MigrateCommand.cs
index 9a61d3a3e..54f9a56a2 100644
--- a/src/dotnet/commands/dotnet-migrate/MigrateCommand.cs
+++ b/src/dotnet/commands/dotnet-migrate/MigrateCommand.cs
@@ -109,17 +109,18 @@ namespace Microsoft.DotNet.Tools.Migrate
                 return;
             }
 
-            List<string> csprojFilesToAdd = new List<string>();
+            var csprojFilesToAdd = new HashSet<string>();
 
             var slnPathWithTrailingSlash = PathUtility.EnsureTrailingSlash(_slnFile.BaseDirectory);
             foreach (var report in migrationReport.ProjectMigrationReports)
             {
                 var reportPathWithTrailingSlash = PathUtility.EnsureTrailingSlash(report.ProjectDirectory);
-                var reportRelPath = Path.Combine(
-                    PathUtility.GetRelativePath(slnPathWithTrailingSlash, reportPathWithTrailingSlash),
-                    report.ProjectName + ".xproj");
+                var relReportPath = PathUtility.GetRelativePath(
+                    slnPathWithTrailingSlash,
+                    reportPathWithTrailingSlash);
 
-                var projects = _slnFile.Projects.Where(p => p.FilePath == reportRelPath);
+                var xprojPath = Path.Combine(relReportPath, report.ProjectName + ".xproj");
+                var projects = _slnFile.Projects.Where(p => p.FilePath == xprojPath);
 
                 var migratedProjectName = report.ProjectName + ".csproj";
                 if (projects.Count() == 1)
@@ -132,7 +133,15 @@ namespace Microsoft.DotNet.Tools.Migrate
                 }
                 else
                 {
-                    csprojFilesToAdd.Add(Path.Combine(report.ProjectDirectory, migratedProjectName));
+                    var csprojPath = Path.Combine(relReportPath, migratedProjectName);
+                    var slnAlreadyContainsMigratedCsproj = _slnFile.Projects
+                        .Where(p => p.FilePath == csprojPath)
+                        .Any();
+
+                    if (!slnAlreadyContainsMigratedCsproj)
+                    {
+                        csprojFilesToAdd.Add(Path.Combine(report.ProjectDirectory, migratedProjectName));
+                    }
                 }
 
                 foreach (var preExisting in report.PreExistingCsprojDependencies)
diff --git a/test/dotnet-migrate.Tests/GivenThatIWantToMigrateSolutions.cs b/test/dotnet-migrate.Tests/GivenThatIWantToMigrateSolutions.cs
index 17ee1299a..2111a9ac7 100644
--- a/test/dotnet-migrate.Tests/GivenThatIWantToMigrateSolutions.cs
+++ b/test/dotnet-migrate.Tests/GivenThatIWantToMigrateSolutions.cs
@@ -38,6 +38,24 @@ namespace Microsoft.DotNet.Migration.Tests
                 "PJAppWithSlnAndXprojRefThatRefsCsprojWhereSlnDoesNotRefCsproj");
         }
 
+        [Fact]
+        public void WhenSolutionContainsACsprojFileItDoesNotTryToAddItAgain()
+        {
+            var projectDirectory = TestAssets
+                .Get("NonRestoredTestProjects", "PJAppWithSlnAndOneAlreadyMigratedCsproj")
+                .CreateInstance()
+                .WithSourceFiles()
+                .Root;
+
+            var solutionRelPath = Path.Combine("TestApp", "TestApp.sln");
+            var cmd = new DotnetCommand()
+                .WithWorkingDirectory(projectDirectory)
+                .ExecuteWithCapturedOutput($"migrate \"{solutionRelPath}\"");
+            cmd.Should().Pass();
+            cmd.StdOut.Should().NotContain("already contains project");
+            cmd.StdErr.Should().BeEmpty();
+        }
+
         private void MigrateAndBuild(string groupName, string projectName, [CallerMemberName] string callingMethod = "", string identifier = "")
         {
             var projectDirectory = TestAssets