diff --git a/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/SameFileSpecificationFixture.cs b/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/SameFileSpecificationFixture.cs
new file mode 100644
index 000000000..01853ee3b
--- /dev/null
+++ b/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/SameFileSpecificationFixture.cs
@@ -0,0 +1,96 @@
+using System.Linq;
+using FizzWare.NBuilder;
+using FluentAssertions;
+using Marr.Data;
+using NUnit.Framework;
+using NzbDrone.Core.MediaFiles;
+using NzbDrone.Core.MediaFiles.EpisodeImport.Specifications;
+using NzbDrone.Core.Parser.Model;
+using NzbDrone.Core.Test.Framework;
+using NzbDrone.Core.Tv;
+
+namespace NzbDrone.Core.Test.MediaFiles.EpisodeImport.Specifications
+{
+    [TestFixture]
+    public class SameFileSpecificationFixture : CoreTest<SameFileSpecification>
+    {
+        private LocalEpisode _localEpisode;
+
+        [SetUp]
+        public void Setup()
+        {
+            _localEpisode = Builder<LocalEpisode>.CreateNew()
+                                                 .With(l => l.Size = 150.Megabytes())
+                                                 .Build();
+        }
+
+        [Test]
+        public void should_be_accepted_if_no_existing_file()
+        {
+            _localEpisode.Episodes = Builder<Episode>.CreateListOfSize(1)
+                                                     .TheFirst(1)
+                                                     .With(e => e.EpisodeFileId = 0)
+                                                     .BuildList();
+
+            Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeTrue();
+        }
+
+        [Test]
+        public void should_be_accepted_if_multiple_existing_files()
+        {
+            _localEpisode.Episodes = Builder<Episode>.CreateListOfSize(2)
+                                                     .TheFirst(1)
+                                                     .With(e => e.EpisodeFileId = 1)
+                                                     .With(e => e.EpisodeFile = new LazyLoaded<EpisodeFile>(
+                                                                                new EpisodeFile
+                                                                                {
+                                                                                    Size = _localEpisode.Size
+                                                                                }))
+                                                     .TheNext(1)
+                                                     .With(e => e.EpisodeFileId = 2)
+                                                     .With(e => e.EpisodeFile = new LazyLoaded<EpisodeFile>(
+                                                                                new EpisodeFile
+                                                                                {
+                                                                                    Size = _localEpisode.Size
+                                                                                }))
+                                                     .Build()
+                                                     .ToList();
+
+            Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeTrue();
+        }
+
+        [Test]
+        public void should_be_accepted_if_file_size_is_different()
+        {
+            _localEpisode.Episodes = Builder<Episode>.CreateListOfSize(1)
+                                                     .TheFirst(1)
+                                                     .With(e => e.EpisodeFileId = 1)
+                                                     .With(e => e.EpisodeFile = new LazyLoaded<EpisodeFile>(
+                                                                                new EpisodeFile
+                                                                                {
+                                                                                    Size = _localEpisode.Size + 100.Megabytes()
+                                                                                }))
+                                                     .Build()
+                                                     .ToList();
+
+            Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeTrue();
+        }
+
+        [Test]
+        public void should_be_reject_if_file_size_is_the_same()
+        {
+            _localEpisode.Episodes = Builder<Episode>.CreateListOfSize(1)
+                                                     .TheFirst(1)
+                                                     .With(e => e.EpisodeFileId = 1)
+                                                     .With(e => e.EpisodeFile = new LazyLoaded<EpisodeFile>(
+                                                                                new EpisodeFile
+                                                                                {
+                                                                                    Size = _localEpisode.Size
+                                                                                }))
+                                                     .Build()
+                                                     .ToList();
+
+            Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeFalse();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj b/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
index c6bb11441..9b325cfb8 100644
--- a/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
+++ b/src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
@@ -283,6 +283,7 @@
     <Compile Include="MediaFiles\EpisodeImport\SampleServiceFixture.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\FreeSpaceSpecificationFixture.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\FullSeasonSpecificationFixture.cs" />
+    <Compile Include="MediaFiles\EpisodeImport\Specifications\SameFileSpecificationFixture.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\GrabbedReleaseQualityFixture.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\MatchesFolderSpecificationFixture.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\NotSampleSpecificationFixture.cs" />
diff --git a/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/SameFileSpecification.cs b/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/SameFileSpecification.cs
new file mode 100644
index 000000000..9876ff492
--- /dev/null
+++ b/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/SameFileSpecification.cs
@@ -0,0 +1,42 @@
+using System.Linq;
+using NLog;
+using NzbDrone.Core.DecisionEngine;
+using NzbDrone.Core.Download;
+using NzbDrone.Core.Parser.Model;
+
+namespace NzbDrone.Core.MediaFiles.EpisodeImport.Specifications
+{
+    public class SameFileSpecification : IImportDecisionEngineSpecification
+    {
+        private readonly Logger _logger;
+
+        public SameFileSpecification(Logger logger)
+        {
+            _logger = logger;
+        }
+        public Decision IsSatisfiedBy(LocalEpisode localEpisode, DownloadClientItem downloadClientItem)
+        {
+            var episodeFiles = localEpisode.Episodes.Where(e => e.EpisodeFileId != 0).Select(e => e.EpisodeFile).ToList();
+
+            if (episodeFiles.Count == 0)
+            {
+                _logger.Debug("No existing episode file, skipping");
+                return Decision.Accept();
+            }
+
+            if (episodeFiles.Count > 1)
+            {
+                _logger.Debug("More than one existing episode file, skipping.");
+                return Decision.Accept();
+            }
+
+            if (episodeFiles.First().Value.Size == localEpisode.Size)
+            {
+                _logger.Debug("'{0}' Has the same filesize as existing file", localEpisode.Path);
+                return Decision.Reject("Has the same filesize as existing file");
+            }
+
+            return Decision.Accept();
+        }
+    }
+}
diff --git a/src/NzbDrone.Core/NzbDrone.Core.csproj b/src/NzbDrone.Core/NzbDrone.Core.csproj
index 44b043ace..8b8e8de54 100644
--- a/src/NzbDrone.Core/NzbDrone.Core.csproj
+++ b/src/NzbDrone.Core/NzbDrone.Core.csproj
@@ -754,6 +754,7 @@
     <Compile Include="MediaFiles\EpisodeImport\DetectSample.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Manual\ManuallyImportedFile.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\FreeSpaceSpecification.cs" />
+    <Compile Include="MediaFiles\EpisodeImport\Specifications\SameFileSpecification.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\GrabbedReleaseQualitySpecification.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\MatchesFolderSpecification.cs" />
     <Compile Include="MediaFiles\EpisodeImport\Specifications\FullSeasonSpecification.cs" />