In a group communications system, a group watcher module subscribes to presentities of interest for a particular group by communicating, to at least one presence server module, a set of subscriptions to a plurality of presentities, wherein each subscription contains a set of event notification criteria for a presentity. When the group watcher module detects a change in presence information for the set of subscriptions, it determines current members of the group and distributes the change in presence information to the current members.