In mobile ad hoc radio networks, mechanisms on how to access the radio channel are extremely important in order to improve network efficiency. In this paper, the load adaptable medium access control for ad hoc networks (LAMAN) protocol is described. LAMAN is a novel decentralized multipacket MAC protocol designed following a cross-layer approach. Basically, this protocol is a hybrid CDMA-TDMA-based protocol that aims at throughput maximization in multipacket communication environments by efficiently combining contention and conflict-free protocol components. Such a combination of components is used to adapt the nodes’ access priority to changes on the traffic load while, at the same time, accounting for the multipacket reception (MPR) capability of the receivers. A theoretical analysis of the system is developed presenting closed expressions of network throughput and packet delay. By simulations, the validity of our analysis is shown and the performances of a LAMAN-based system and an Aloha-CDMA-based one are compared.