This study compares the creativity of 4-man groups under 2 conditions of leadership. The Ss were 90 freshman and sophomore Navy ROTC midshipmen and 30 NROTC seniors who served as group leaders. In IS of the groups, the leaders acted as chairmen who directed the group discussions and contributed to the task solution. In the other 15 groups, leaders acted in a capacity: they directed and guided group discussion and they were allowed to encourage members or to reject ideas, but the leaders were prohibited from contributing to the solution of the task. Groups having leaders were generally superior in quantity of output while groups under leaders were superior in the quality of the product. Although leaders in the 2 conditions did not differ in their satisfaction with the group product, the leaders were more satisfied with their own individual contribution to the task. The leadership styles did not produce differences in the members' esteem for the leader or in the members' morale and satisfaction with the task. Differences were found in the influence of the leader intelligence and ability scores on group creativity. The present study compares two types of leadership conditions; namely, the more usual participatory situation in which the chairman of the group contributes freely to the group discussion, and a supervisory condition in which the leader acts as the coordinator and evaluator of the group's problem solving attempts. The condition of leadership, although here artificially created, is not at all uncommon in real life. A director of a research program, or the supervisor of a project, frequently assigns problem solving and development tasks to a group of subordinates who then report back to him at appropriate intervals to obtain further guidance and critique. This latter experimental conditon is, thus, also related to some extent to the studies by Parnes and Meadow (1959) and Meadow,