Advances in cooperative communications and directional antenna design so far have taken place in parallel, if not in isolation from each other. To explore the role they may play in the next generation of wireless networks, it is important to design and evaluate protocols that can provide co-opdirectionality, the capability of tapping into the combined potential of both cooperation and transmission directionality. Inspired by the protocols presented in  and , we propose a novel co-opdirectional MAC that fully leverages both cooperation diversity and transmission directionality. Special attention has been paid to the protocol design so that the new MAC would not only inherit the advantages of two previous protocols, but also avoid their weaknesses in the wireless ad hoc environment. The protocol thus delivers a superior performance, as our extensive simulations confirm. To the best knowledge of the authors, this paper represents the first effort to deal with the challenges of integrating cooperation and directional capabilities at the MAC layer.