The present invention presents a solution for prioritizing instant messaging (IM) communications based on sender/receiver relationships and for presenting selective notifications based upon the established priorities. The invention can include a data store, a message prioritization engine, and a client-side IM application. The data store can manage information describing relationships among people and recipient configurable IM prioritizing information. The message prioritization engine can determine a priority value for IM communications based upon the relationships and recipient configurable IM prioritizing information of the data store. The client-side IM application can receive IM messages that have an associated priority value established by the message prioritization engine. The client-side application can present an indicator of the priority value for associated IM messages within a user interface. In one embodiment, the information describing relationships used by the prioritization engine can be acquired from at least one social networking system.