A wireless ad-hoc network is a dynamically reconfigurable network without any fixed infrastructure or centralized administration. Due to the limited radio propagation range of wireless devices, communication between them in a wireless ad-hoc network is often achieved by multi-hop routing. In wireless ad-hoc networks, many applications use multicasting for the efficient dissemination of queries or data. Since a large number of multicast packets may decrease the stability of the network, it is important to reduce the number of packets required for multicasting. In this paper, we propose an efficient multicast algorithm for wireless ad-hoc networks that can reduce the number of multicast packets effectively. The proposed method clusters the multicast receivers hierarchically based on their directions from the multicast sender. Then, the hierarchically organized cluster is used for multicasting path. Through simulation experiments, we evaluate the performance of the proposed method in comparison with conventional multicasting methods.