A method and system for presence state assignment based on schedule information in an instant messenger system. In one embodiment, the method may include storing schedule information corresponding to a given user, where the schedule information is indicative of an activity status of the given user at a given time. The method may further include querying the schedule information, and if a current presence state of an instant messenger does not correspond to the activity status indicated by the schedule information, assigning a different presence state that corresponds to the activity status in response to the querying, where the current presence state and the different presence state each correspond to the given user.