The characteristics of a group's task have been shown to account for more than half the variation in group interaction. In the context of group support systems (GSS), the importance of task has been underscored by the recommendation that achieving a fit between task and technology should be a principle for effective GSS use. Although the body of group support systems research has grown in recent years, and experience with different tasks and technologies now exists, no generally accepted theory of task/technology fit has emerged. This paper develops a theory of task/technology fit in GSS environments based on attributes of task complexity and their relationship to relevant dimensions of GSS technology. Propositions to guide further research are developed from the theory.