This research examines how different levels of task-technology fit can impact collaboration technology effectiveness and efficiency over time. The results of a longitudinal experiment indicate that initially, teams using poor-fitting collaboration technology had lower effectiveness and efficiency, satisfaction, and perceptions of fit than teams using fitting collaboration technology. Over time, however, poor-fit teams improved while fit teams remained consistent, thereby eliminating the initial differences in measured outcomes between poor-fit and fit teams. The results suggest that task-technology fit may be more relevant as a predictor of effectiveness and efficiency in contexts where the task and the collaboration technology are less malleable.