Achieving student participation, it has been argued, is one of the most important challenges in distance education. This explorative study examines whether a synchronous communication medium, instant messaging (IM), may enable students to participate more actively in online group work. When comparing two groups that adopted IM with two groups that didn't it was found that the adopters had a higher sense of participation and spent more time working with the content and communicating with their peers. Moreover, the social networks of the adopters were slightly denser. Thus, the study indicates that the groups that adopted IM operated with a higher level of participation, although it should be noted that these results are based on a small group of students. All groups used e-mail for group interactions but the adopters also used IM as a complement to e-mail. This paper concludes by calling for more research to test the results of this study in other contexts. (Contains 6 tables and 2 figures.)