diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs
index b9cd1c9..5ec9da3 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs
@@ -97,6 +97,7 @@ namespace Cysharp.Threading.Tasks
             IProgress<float> progress;
             CancellationToken cancellationToken;
             CancellationTokenRegistration cancellationTokenRegistration;
+            bool cancelImmediately;
             bool completed;
 
             UniTaskCompletionSourceCore<AsyncUnit> core;
@@ -123,6 +124,7 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.cancelImmediately = cancelImmediately;
                 result.completed = false;
                 
                 asyncOperation.completed += result.continuationAction;
@@ -152,7 +154,8 @@ namespace Cysharp.Threading.Tasks
                 }
                 finally
                 {
-                    TryReturn();
+                    if (!(cancelImmediately && cancellationToken.IsCancellationRequested))
+                        TryReturn();
                 }
             }
 
@@ -209,6 +212,7 @@ namespace Cysharp.Threading.Tasks
                 progress = default;
                 cancellationToken = default;
                 cancellationTokenRegistration.Dispose();
+                cancelImmediately = default;
                 return pool.TryPush(this);
             }
 
@@ -320,6 +324,7 @@ namespace Cysharp.Threading.Tasks
             IProgress<float> progress;
             CancellationToken cancellationToken;
             CancellationTokenRegistration cancellationTokenRegistration;
+            bool cancelImmediately;
             bool completed;
 
             UniTaskCompletionSourceCore<UnityEngine.Object> core;
@@ -346,6 +351,7 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.cancelImmediately = cancelImmediately;
                 result.completed = false;
                 
                 asyncOperation.completed += result.continuationAction;
@@ -375,7 +381,8 @@ namespace Cysharp.Threading.Tasks
                 }
                 finally
                 {
-                    TryReturn();
+                    if (!(cancelImmediately && cancellationToken.IsCancellationRequested))
+                        TryReturn();
                 }
             }
 
@@ -436,6 +443,7 @@ namespace Cysharp.Threading.Tasks
                 progress = default;
                 cancellationToken = default;
                 cancellationTokenRegistration.Dispose();
+                cancelImmediately = default;
                 return pool.TryPush(this);
             }
 
@@ -548,6 +556,7 @@ namespace Cysharp.Threading.Tasks
             IProgress<float> progress;
             CancellationToken cancellationToken;
             CancellationTokenRegistration cancellationTokenRegistration;
+            bool cancelImmediately;
             bool completed;
 
             UniTaskCompletionSourceCore<UnityEngine.Object> core;
@@ -574,6 +583,7 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.cancelImmediately = cancelImmediately;
                 result.completed = false;
                 
                 asyncOperation.completed += result.continuationAction;
@@ -603,7 +613,8 @@ namespace Cysharp.Threading.Tasks
                 }
                 finally
                 {
-                    TryReturn();
+                    if (!(cancelImmediately && cancellationToken.IsCancellationRequested))
+                        TryReturn();
                 }
             }
 
@@ -664,6 +675,7 @@ namespace Cysharp.Threading.Tasks
                 progress = default;
                 cancellationToken = default;
                 cancellationTokenRegistration.Dispose();
+                cancelImmediately = default;
                 return pool.TryPush(this);
             }
 
@@ -777,6 +789,7 @@ namespace Cysharp.Threading.Tasks
             IProgress<float> progress;
             CancellationToken cancellationToken;
             CancellationTokenRegistration cancellationTokenRegistration;
+            bool cancelImmediately;
             bool completed;
 
             UniTaskCompletionSourceCore<AssetBundle> core;
@@ -803,6 +816,7 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.cancelImmediately = cancelImmediately;
                 result.completed = false;
                 
                 asyncOperation.completed += result.continuationAction;
@@ -832,7 +846,8 @@ namespace Cysharp.Threading.Tasks
                 }
                 finally
                 {
-                    TryReturn();
+                    if (!(cancelImmediately && cancellationToken.IsCancellationRequested))
+                        TryReturn();
                 }
             }
 
@@ -893,6 +908,7 @@ namespace Cysharp.Threading.Tasks
                 progress = default;
                 cancellationToken = default;
                 cancellationTokenRegistration.Dispose();
+                cancelImmediately = default;
                 return pool.TryPush(this);
             }
 
@@ -1021,6 +1037,7 @@ namespace Cysharp.Threading.Tasks
             IProgress<float> progress;
             CancellationToken cancellationToken;
             CancellationTokenRegistration cancellationTokenRegistration;
+            bool cancelImmediately;
             bool completed;
 
             UniTaskCompletionSourceCore<UnityWebRequest> core;
@@ -1047,6 +1064,7 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.cancelImmediately = cancelImmediately;
                 result.completed = false;
                 
                 asyncOperation.completed += result.continuationAction;
@@ -1077,7 +1095,8 @@ namespace Cysharp.Threading.Tasks
                 }
                 finally
                 {
-                    TryReturn();
+                    if (!(cancelImmediately && cancellationToken.IsCancellationRequested))
+                        TryReturn();
                 }
             }
 
@@ -1146,6 +1165,7 @@ namespace Cysharp.Threading.Tasks
                 progress = default;
                 cancellationToken = default;
                 cancellationTokenRegistration.Dispose();
+                cancelImmediately = default;
                 return pool.TryPush(this);
             }
 
diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt
index 0516fef..ebcfa93 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt
@@ -165,6 +165,7 @@ namespace Cysharp.Threading.Tasks
             IProgress<float> progress;
             CancellationToken cancellationToken;
             CancellationTokenRegistration cancellationTokenRegistration;
+            bool cancelImmediately;
             bool completed;
 
             UniTaskCompletionSourceCore<<#= IsVoid(t) ? "AsyncUnit" : t.returnType #>> core;
@@ -191,6 +192,7 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.cancelImmediately = cancelImmediately;
                 result.completed = false;
                 
                 asyncOperation.completed += result.continuationAction;
@@ -227,7 +229,8 @@ namespace Cysharp.Threading.Tasks
                 }
                 finally
                 {
-                    TryReturn();
+                    if (!(cancelImmediately && cancellationToken.IsCancellationRequested))
+                        TryReturn();
                 }
             }
 
@@ -304,6 +307,7 @@ namespace Cysharp.Threading.Tasks
                 progress = default;
                 cancellationToken = default;
                 cancellationTokenRegistration.Dispose();
+                cancelImmediately = default;
                 return pool.TryPush(this);
             }