Distributed applications using file sharing and file replication, conferencing, and delivery in multimedia systems often need to use the semantics of causal multicast. Causal multicast in a mobile system is complicated by the various limitations imposed by the mobile system. Though there are different directions to improve the performance of causal multicast algorithms in mobile systems, at the core of such algorithms is the module to impose causal delivery among a set of nodes — which may be either mobile hosts, or mobile service stations, or peers at a higher level in the interconnection hierarchy. We show how to adapt the optimal causal multicast algorithm of Kshemkalyani-Singhal to mobile networks, and then show simulation results comparing its performance with that of other algorithms for causal multicast in mobile networks.