A dynamic contact list management (DCLM) method and system operable in a communications network environment. In one embodiment, upon receiving a communication request from an originating party over a first network towards a networked party, a query is generated for determining and locating an IM address associated with the originating party. Upon establishing presence awareness between the originating party and the networked party, the IM address of the originating party is added to a contact list database associated with the networked party. The IM address, which is persistent at least for the duration of a first communication session established responsive to the communication request, may be used for engaging in a second communication session between the parties.