IEEE 802.15 task group 8 (IEEE 802.15.8) has been recently chartered to define PHY and MAC mechanism for wireless personal area networks (WPAN) peer aware communications (PAC) optimized for peer to peer and infrastructureless communications with fully distributed coordination. The most promising services created by IEEE 802.15.8 would be multicast communication with simultaneous membership in multiple groups, typically up to 10, in dense network topology. Most existing multicast techniques in mobile ad hoc networks (MANET) have relied upon a central coordinator to manage its multicast group and thus cannot be used for fully-distributed PAC networks. In this paper, we propose a graph-based multicast routing protocol referred to as fully-distributed multicast routing protocol (FDMRP) for IEEE 802.15.8 PAC networks. The FDMRP minimizes routing table entries and thus reduces control message overhead for its multicast group management. To balance the control message, all nodes in the network have a similar number of routing entries to manage nodes in a same multicast group. To measure the effectiveness of the proposed FDMRP against the ODMRP , we evaluated performance by OPNET simulator. Performance evaluation shows that the FDMRP shows less control message overhead and multicast group join latency than the ODMRP.