diff --git a/src/AnthropicClient/AnthropicApiClient.cs b/src/AnthropicClient/AnthropicApiClient.cs
index 8c0b3fb..34244c3 100644
--- a/src/AnthropicClient/AnthropicApiClient.cs
+++ b/src/AnthropicClient/AnthropicApiClient.cs
@@ -55,6 +55,13 @@ public interface IAnthropicApiClient
   /// <returns>An asynchronous enumerable that yields the response as an <see cref="AnthropicResult{T}"/> where T is <see cref="Page{T}"/> where T is <see cref="MessageBatchResponse"/>.</returns>
   IAsyncEnumerable<AnthropicResult<Page<MessageBatchResponse>>> ListAllMessageBatchesAsync(int limit = 20);
 
+  /// <summary>
+  /// Cancels a message batch asynchronously.
+  /// </summary>
+  /// <param name="batchId">The ID of the message batch to cancel.</param>
+  /// <returns>A task that represents the asynchronous operation. The task result contains the response as an <see cref="AnthropicResult{T}"/> where T is <see cref="MessageBatchResponse"/>.</returns>
+  Task<AnthropicResult<MessageBatchResponse>> CancelMessageBatchAsync(string batchId);
+
   /// <summary>
   /// Gets the results of a message batch asynchronously.
   /// </summary>
@@ -384,6 +391,24 @@ public class AnthropicApiClient : IAnthropicApiClient
     }
   }
 
+  /// <inheritdoc/>
+  public async Task<AnthropicResult<MessageBatchResponse>> CancelMessageBatchAsync(string batchId)
+  {
+    var endpoint = $"{MessageBatchesEndpoint}/{batchId}/cancel";
+    var response = await SendRequestAsync(endpoint, HttpMethod.Post);
+    var anthropicHeaders = new AnthropicHeaders(response.Headers);
+    var responseContent = await response.Content.ReadAsStringAsync();
+
+    if (response.IsSuccessStatusCode is false)
+    {
+      var error = Deserialize<AnthropicError>(responseContent) ?? new AnthropicError();
+      return AnthropicResult<MessageBatchResponse>.Failure(error, anthropicHeaders);
+    }
+
+    var msgBatchResponse = Deserialize<MessageBatchResponse>(responseContent) ?? new MessageBatchResponse();
+    return AnthropicResult<MessageBatchResponse>.Success(msgBatchResponse, anthropicHeaders);
+  }
+
   /// <inheritdoc/>
   public async Task<AnthropicResult<IAsyncEnumerable<MessageBatchResultItem>>> GetMessageBatchResultsAsync(string batchId)
   {
@@ -533,9 +558,10 @@ public class AnthropicApiClient : IAnthropicApiClient
     return new ToolCall(tool, toolUse);
   }
 
-  private async Task<HttpResponseMessage> SendRequestAsync(string endpoint)
+  private async Task<HttpResponseMessage> SendRequestAsync(string endpoint, HttpMethod? method = null)
   {
-    return await _httpClient.GetAsync(endpoint);
+    var request = new HttpRequestMessage(method ?? HttpMethod.Get, endpoint);
+    return await _httpClient.SendAsync(request);
   }
 
   private async Task<HttpResponseMessage> SendRequestAsync<T>(string endpoint, T request)
diff --git a/tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs b/tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs
index 2b458c2..8b312c2 100644
--- a/tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs
+++ b/tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs
@@ -1282,26 +1282,26 @@ public class AnthropicApiClientTests : IntegrationTest
     var result = await Client.GetMessageBatchAsync(batchId);
 
     result.IsSuccess.Should().BeTrue();
-    result.Value.Should().BeOfType<MessageBatchResponse>();
-    result.Value.Id.Should().Be("msgbatch_013Zva2CMHLNnXjNJJKqJ2EF");
-    result.Value.Type.Should().Be("message_batch");
-    result.Value.ProcessingStatus.Should().Be("in_progress");
-    result.Value.RequestCounts.Should().BeEquivalentTo(new MessageBatchRequestCounts
+    result.Value.Should().BeEquivalentTo(new MessageBatchResponse()
     {
-      Processing = 100,
-      Succeeded = 50,
-      Errored = 30,
-      Canceled = 10,
-      Expired = 10
+      Id = "msgbatch_013Zva2CMHLNnXjNJJKqJ2EF",
+      Type = "message_batch",
+      ProcessingStatus = "in_progress",
+      RequestCounts = new MessageBatchRequestCounts
+      {
+        Processing = 100,
+        Succeeded = 50,
+        Errored = 30,
+        Canceled = 10,
+        Expired = 10
+      },
+      EndedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      CreatedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      ExpiresAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      ArchivedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      CancelInitiatedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      ResultsUrl = "https://api.anthropic.com/v1/messages/batches/msgbatch_013Zva2CMHLNnXjNJJKqJ2EF/results"
     });
-
-    result.Value.EndedAt.Should().Be(DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"));
-    result.Value.CreatedAt.Should().Be(DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"));
-    result.Value.ExpiresAt.Should().Be(DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"));
-    result.Value.ArchivedAt.Should().Be(DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"));
-    result.Value.CancelInitiatedAt.Should().Be(DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"));
-    result.Value.ResultsUrl.Should()
-      .Be("https://api.anthropic.com/v1/messages/batches/msgbatch_013Zva2CMHLNnXjNJJKqJ2EF/results");
   }
 
   [Fact]
@@ -1823,4 +1823,85 @@ public class AnthropicApiClientTests : IntegrationTest
       }
     });
   }
+
+  [Fact]
+  public async Task CancelMessageBatchAsync_WhenCalled_ItShouldReturnBatch()
+  {
+    var batchId = "msgbatch_013Zva2CMHLNnXjNJJKqJ2EF";
+
+    _mockHttpMessageHandler
+      .WhenCancelMessageBatchRequest(batchId)
+      .Respond(
+        HttpStatusCode.OK,
+        "application/json",
+        @"{
+            ""id"": ""msgbatch_013Zva2CMHLNnXjNJJKqJ2EF"",
+            ""type"": ""message_batch"",
+            ""processing_status"": ""in_progress"",
+            ""request_counts"": {
+              ""processing"": 100,
+              ""succeeded"": 50,
+              ""errored"": 30,
+              ""canceled"": 10,
+              ""expired"": 10
+            },
+            ""ended_at"": ""2024-08-20T18:37:24.100435Z"",
+            ""created_at"": ""2024-08-20T18:37:24.100435Z"",
+            ""expires_at"": ""2024-08-20T18:37:24.100435Z"",
+            ""archived_at"": ""2024-08-20T18:37:24.100435Z"",
+            ""cancel_initiated_at"": ""2024-08-20T18:37:24.100435Z"",
+            ""results_url"": ""https://api.anthropic.com/v1/messages/batches/msgbatch_013Zva2CMHLNnXjNJJKqJ2EF/results""
+          }"
+      );
+
+    var result = await Client.CancelMessageBatchAsync(batchId);
+
+    result.IsSuccess.Should().BeTrue();
+    result.Value.Should().BeEquivalentTo(new MessageBatchResponse()
+    {
+      Id = "msgbatch_013Zva2CMHLNnXjNJJKqJ2EF",
+      Type = "message_batch",
+      ProcessingStatus = "in_progress",
+      RequestCounts = new MessageBatchRequestCounts
+      {
+        Processing = 100,
+        Succeeded = 50,
+        Errored = 30,
+        Canceled = 10,
+        Expired = 10
+      },
+      EndedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      CreatedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      ExpiresAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      ArchivedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      CancelInitiatedAt = DateTimeOffset.Parse("2024-08-20T18:37:24.100435Z"),
+      ResultsUrl = "https://api.anthropic.com/v1/messages/batches/msgbatch_013Zva2CMHLNnXjNJJKqJ2EF/results"
+    });
+  }
+
+  [Fact]
+  public async Task CancelMessageBatchAsync_WhenCalledAndFails_ItShouldReturnError()
+  {
+    var batchId = "msgbatch_013Zva2CMHLNnXjNJJKqJ2EF";
+
+    _mockHttpMessageHandler
+      .WhenCancelMessageBatchRequest(batchId)
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+            ""type"": ""error"",
+            ""error"": {
+              ""type"": ""invalid_request_error"",
+              ""message"": ""batch: batch not found""
+            }
+          }"
+      );
+
+    var result = await Client.CancelMessageBatchAsync(batchId);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
 }
\ No newline at end of file
diff --git a/tests/AnthropicClient.Tests/Integration/IntegrationTest.cs b/tests/AnthropicClient.Tests/Integration/IntegrationTest.cs
index 465319d..e521d0c 100644
--- a/tests/AnthropicClient.Tests/Integration/IntegrationTest.cs
+++ b/tests/AnthropicClient.Tests/Integration/IntegrationTest.cs
@@ -91,4 +91,10 @@ public static class MockHttpMessageHandlerExtensions
     return mockHttpMessageHandler
       .SetupBaseRequest(HttpMethod.Get, MessageBatchesEndpoint);
   }
+
+  public static MockedRequest WhenCancelMessageBatchRequest(this MockHttpMessageHandler mockHttpMessageHandler, string batchId)
+  {
+    return mockHttpMessageHandler
+      .SetupBaseRequest(HttpMethod.Post, $"{MessageBatchesEndpoint}/{batchId}/cancel");
+  }
 }
\ No newline at end of file