diff --git a/src/NATS.Client.JetStream/INatsJSContext.cs b/src/NATS.Client.JetStream/INatsJSContext.cs
index a23eff2c8..bc1c89e41 100644
--- a/src/NATS.Client.JetStream/INatsJSContext.cs
+++ b/src/NATS.Client.JetStream/INatsJSContext.cs
@@ -208,6 +208,20 @@ ValueTask<INatsJSStream> CreateStreamAsync(
         StreamConfig config,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    /// Creates a new stream if it doesn't exist or update if the stream already exists.
+    /// </summary>
+    /// <param name="config">Stream configuration request to be sent to NATS JetStream server.</param>
+    /// <param name="cancellationToken">A <see cref="CancellationToken"/> used to cancel the API call.</param>
+    /// <returns>The NATS JetStream stream object which can be used to manage the stream.</returns>
+    /// <exception cref="NatsJSException">There was an issue retrieving the response.</exception>
+    /// <exception cref="NatsJSApiException">Server responded with an error.</exception>
+    /// <exception cref="ArgumentException">The stream name in <paramref name="config"/> is invalid.</exception>
+    /// <exception cref="ArgumentNullException">The name in <paramref name="config"/> is <c>null</c>.</exception>
+    ValueTask<INatsJSStream> CreateOrUpdateStreamAsync(
+        StreamConfig config,
+        CancellationToken cancellationToken = default);
+
     /// <summary>
     /// Deletes a stream.
     /// </summary>
diff --git a/src/NATS.Client.JetStream/NatsJSContext.Streams.cs b/src/NATS.Client.JetStream/NatsJSContext.Streams.cs
index b9b428b89..135d33457 100644
--- a/src/NATS.Client.JetStream/NatsJSContext.Streams.cs
+++ b/src/NATS.Client.JetStream/NatsJSContext.Streams.cs
@@ -59,6 +59,33 @@ public async ValueTask<INatsJSStream> CreateStreamAsync(
         return new NatsJSStream(this, response);
     }
 
+    /// <summary>
+    /// Creates a new stream if it doesn't exist or update if the stream already exists.
+    /// </summary>
+    /// <param name="config">Stream configuration request to be sent to NATS JetStream server.</param>
+    /// <param name="cancellationToken">A <see cref="CancellationToken"/> used to cancel the API call.</param>
+    /// <returns>The NATS JetStream stream object which can be used to manage the stream.</returns>
+    /// <exception cref="NatsJSException">There was an issue retrieving the response.</exception>
+    /// <exception cref="NatsJSApiException">Server responded with an error.</exception>
+    /// <exception cref="ArgumentException">The stream name in <paramref name="config"/> is invalid.</exception>
+    /// <exception cref="ArgumentNullException">The name in <paramref name="config"/> is <c>null</c>.</exception>
+    public async ValueTask<INatsJSStream> CreateOrUpdateStreamAsync(StreamConfig config, CancellationToken cancellationToken = default)
+    {
+        ThrowIfInvalidStreamName(config.Name, nameof(config.Name));
+        var response = await JSRequestAsync<StreamConfig, StreamUpdateResponse>(
+            subject: $"{Opts.Prefix}.STREAM.UPDATE.{config.Name}",
+            request: config,
+            cancellationToken);
+
+        if (response.Error is { Code: 404 })
+        {
+            return await CreateStreamAsync(config, cancellationToken);
+        }
+
+        response.EnsureSuccess();
+        return new NatsJSStream(this, response.Response!);
+    }
+
     /// <summary>
     /// Deletes a stream.
     /// </summary>
diff --git a/tests/NATS.Client.JetStream.Tests/JetStreamTest.cs b/tests/NATS.Client.JetStream.Tests/JetStreamTest.cs
index 4cbc9cd6f..310bc9553 100644
--- a/tests/NATS.Client.JetStream.Tests/JetStreamTest.cs
+++ b/tests/NATS.Client.JetStream.Tests/JetStreamTest.cs
@@ -26,6 +26,9 @@ public async Task Stream_invalid_name_test(string? streamName)
         // Create stream
         await Assert.ThrowsAnyAsync<ArgumentException>(async () => await jsmContext.CreateStreamAsync(cfg));
 
+        // Create or update stream
+        await Assert.ThrowsAnyAsync<ArgumentException>(async () => await jsmContext.CreateOrUpdateStreamAsync(cfg));
+
         // Delete stream
         await Assert.ThrowsAnyAsync<ArgumentException>(async () => await jsmContext.DeleteStreamAsync(streamName!));
 
diff --git a/tests/NATS.Client.JetStream.Tests/ManageStreamTest.cs b/tests/NATS.Client.JetStream.Tests/ManageStreamTest.cs
index c36db8ab3..7f607319b 100644
--- a/tests/NATS.Client.JetStream.Tests/ManageStreamTest.cs
+++ b/tests/NATS.Client.JetStream.Tests/ManageStreamTest.cs
@@ -127,4 +127,61 @@ public async Task Delete_one_msg()
 
         Assert.Equal(2, stream.Info.State.Subjects?.Count);
     }
+
+    [Fact]
+    public async Task Create_or_update_stream_should_be_create_stream_if_stream_doesnt_exist()
+    {
+        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+
+        await using var server = NatsServer.StartJS();
+        var nats = server.CreateClientConnection();
+        var js = new NatsJSContext(nats);
+
+        var streamConfig = new StreamConfig("s1", ["s1.*"])
+        { Storage = StreamConfigStorage.File };
+
+        var accountInfoBefore = await js.GetAccountInfoAsync(cts.Token);
+        await js.CreateOrUpdateStreamAsync(streamConfig, cts.Token);
+        var accountInfoAfter = await js.GetAccountInfoAsync(cts.Token);
+
+        Assert.Equal(0, accountInfoBefore.Streams);
+        Assert.Equal(1, accountInfoAfter.Streams);
+    }
+
+    [Fact]
+    public async Task Create_or_update_stream_should_be_update_stream_if_stream_exist()
+    {
+        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+
+        await using var server = NatsServer.StartJS();
+        var nats = server.CreateClientConnection();
+        var js = new NatsJSContext(nats);
+
+        var streamConfig = new StreamConfig("s1", ["s1.*"])
+        { Storage = StreamConfigStorage.File, NoAck = false };
+        var streamConfigForUpdated = streamConfig with { NoAck = true };
+
+        var stream = await js.CreateOrUpdateStreamAsync(streamConfig, cts.Token);
+        var updatedStream = await js.CreateOrUpdateStreamAsync(streamConfigForUpdated, cts.Token);
+
+        Assert.False(stream.Info.Config.NoAck);
+        Assert.True(updatedStream.Info.Config.NoAck);
+    }
+
+    [Fact]
+    public async Task Create_or_update_stream_should_be_throwing_update_operation_errors()
+    {
+        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+
+        await using var server = NatsServer.StartJS();
+        var nats = server.CreateClientConnection();
+        var js = new NatsJSContext(nats);
+
+        var streamConfig = new StreamConfig("s1", ["s1.*"])
+        { Storage = StreamConfigStorage.File };
+        var streamConfigForUpdated = streamConfig with { Storage = StreamConfigStorage.Memory };
+
+        await js.CreateOrUpdateStreamAsync(streamConfig, cts.Token);
+        await Assert.ThrowsAsync<NatsJSApiException>(async () => await js.CreateOrUpdateStreamAsync(streamConfigForUpdated, cts.Token));
+    }
 }
diff --git a/tests/NATS.Client.KeyValueStore.Tests/NatsKVContextFactoryTest.cs b/tests/NATS.Client.KeyValueStore.Tests/NatsKVContextFactoryTest.cs
index f3700d222..d82eac404 100644
--- a/tests/NATS.Client.KeyValueStore.Tests/NatsKVContextFactoryTest.cs
+++ b/tests/NATS.Client.KeyValueStore.Tests/NatsKVContextFactoryTest.cs
@@ -78,6 +78,8 @@ public class MockJsContext : INatsJSContext
 
         public ValueTask<INatsJSStream> CreateStreamAsync(StreamConfig config, CancellationToken cancellationToken = default) => throw new NotImplementedException();
 
+        public ValueTask<INatsJSStream> CreateOrUpdateStreamAsync(StreamConfig config, CancellationToken cancellationToken = default) => throw new NotImplementedException();
+
         public ValueTask<bool> DeleteStreamAsync(string stream, CancellationToken cancellationToken = default) => throw new NotImplementedException();
 
         public ValueTask<StreamPurgeResponse> PurgeStreamAsync(string stream, StreamPurgeRequest request, CancellationToken cancellationToken = default) => throw new NotImplementedException();
diff --git a/tests/NATS.Client.ObjectStore.Tests/NatsObjContextFactoryTest.cs b/tests/NATS.Client.ObjectStore.Tests/NatsObjContextFactoryTest.cs
index adc5eef32..78d94dee2 100644
--- a/tests/NATS.Client.ObjectStore.Tests/NatsObjContextFactoryTest.cs
+++ b/tests/NATS.Client.ObjectStore.Tests/NatsObjContextFactoryTest.cs
@@ -78,6 +78,8 @@ public class MockJsContext : INatsJSContext
 
         public ValueTask<INatsJSStream> CreateStreamAsync(StreamConfig config, CancellationToken cancellationToken = default) => throw new NotImplementedException();
 
+        public ValueTask<INatsJSStream> CreateOrUpdateStreamAsync(StreamConfig config, CancellationToken cancellationToken = default) => throw new NotImplementedException();
+
         public ValueTask<bool> DeleteStreamAsync(string stream, CancellationToken cancellationToken = default) => throw new NotImplementedException();
 
         public ValueTask<StreamPurgeResponse> PurgeStreamAsync(string stream, StreamPurgeRequest request, CancellationToken cancellationToken = default) => throw new NotImplementedException();