A method and system for multicasting messages to wireless terminals. A multicast radio-packet link is established between a packet gateway and a base station system respectively for each cell sector served by the packet gateway. Each multicast link has an active state when any wireless terminals in the corresponding cell sector are in a multicast state prepared to receive multicast messages, and an inactive state when no wireless terminals in the corresponding cell sector are in the multicast state. When the packet gateway receives a multicast message, it sends the message over each active multicast link but not over any inactive multicast link. Thus, a single copy of the multicast message can conveniently be sent just to each of the cell sectors that is currently serving at least one wireless terminal that is in a multicast state.