A question associated with the introduction of computer-supported collaborative learning (CSCL) is whether all participants profit equally from working in CSCL environments. This article reports on a review study into gender-related differences in participation in CSCL. As many of the processes in CSCL are similar to those in computer-mediated communication (CMC), studies into CMC are also included in the review. Male dominance is found to play a role in many CMC settings. A learning culture with an explicit focus on participation by all students seems to be related to a more gender-balanced participation in CMC, however. A tendency for boys to be more active participants than girls is also present in CSCL environments, but it is less pronounced than in CMC. This may be explained by the fact that participation is explicitly promoted in most CSCL environments. Gender differences in the character of students' contributions are found in both CMC and CSCL. It is concluded that in order to avoid gender-stereotyped participation and communication patterns, it is necessary to explicitly address inclusiveness as an aspect of a collaborative classroom culture. A plea is made for further research into differential participation by students in CSCL, and the effects thereof on cognitive and affective learning outcomes. Research should also focus on the question how classroom cultures can be promoted that support active participation of all students aimed at collaborative knowledge construction. © 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd.