This research examined specific team-interactional processes that relate to effective team performance beyond the task proficiency of the individual team members. Subjects were 66 female and 44 male undergraduate volunteers who were assigned to teams of two (“pilot” and “copilot”) in a low-fidelity flight simulation task. Team members were assigned separate tasks (e.g., the pilot operated a joystick and the copilot a keyboard), but the task was divided in a manner that required the team members to coordinate to complete their mission. The measures of task proficiency were the pilot's ability to control the joystick and the copilot's ability to operate the keyboard. The interactive processes examined included such behaviors as providing information in advance, making long- and short-term plans, asking for input, assigning tasks, and stepping in to help others. Effectiveness of the team was determined by an independent measure of mission performance and by the number of targets destroyed in the scenario. Multiple regression analyses revealed that coordination (process) ratings predicted mission performance of the team when individual task proficiency was held constant. The implications for team training are discussed.