We conducted an exploratory study to examine the behaviors and roles that are enacted by emergent leaders in virtual team settings. Specifically, we analyzed quantitative and qualitative data to identify differences between team members who emerged as leaders and as non-leaders in terms of their behavior as manifested in their electronic mail messages. The longitudinal study involved seven ad hoc and temporary virtual teams composed of senior executives of a US federal government agency who participated in an executive development program at a university.The study indicated that overall, the emergent leaders sent more and longer email messages than their team members did. The number of task-oriented messages, particularly those that were related to logistics coordination, sent by emergent leaders was higher than that of non-leaders. However, there were no differences between emergent leaders and non-leaders in terms of expertise-related messages. No significant differences in relationship-oriented and technology management messages between emergent leaders and other team members existed. Furthermore, the emergent leaders enacted three roles: initiator, scheduler, and integrator. These findings are discussed and their implications for research and practice are described in the paper.