—This paper presents a solution to the well-known Test&Set operation in an asynchronous system prone to process crashes. Test&Set is a synchronization operation that, when invoked by a set of processes, returns yes to a unique process and returns no to all the others. Recently many advances in implementing Test&Set objects have been achieved, however all of them uniquely target the shared memory model. In this paper we propose an implementation of a Test&Set object for a message passing distributed system. This implementation can be invoked by any number p<= n of processes where n is the total number of processes in the system. It has an expected individual step complexity in O(\log p) and an expected individual message complexity in O(n). The proposed Test&Set object is built atop a new basic building block, called selector, that allows to select a winning group among two groups of processes. We are not aware of any such results.