Sorry if i was too short. But i saw no problem calling the socket async write method from a different thread. The async write requests a write operation that's gonna be performed asynchronously and when the operation is complete, the io_service::run thread executes the appropriated handler. If you guarantee that only one thread at a time is calling the object's async method, there are no problems with it, i assume. Did i make a mistake(or more than one) in that reasoning?