This study compared professionally-led support groups and leaderless self-help support groups to examine whether the presence or absence of a leader in the group made a difference in verbal interaction and member-to-member helping behaviors. This study utilized a comparative design and paired ten professionally-led groups with ten leaderless groups. Through the use of audio-tapes, group process was examined for differences in verbal interaction using the Hill Interaction Matrix. Members's perceptions of helping behaviors occurring in group meetings were measured with the Helping Processes Questionnaire. Members of the leaderless groups focused more on common interest topics while members of the professionally-led groups concentrated on personal topics, indicating that members may feel more comfortable sharing personal information in the presence of a trained leader, or that leaders more strongly encouraged the sharing of personal material. Members of the professionally-led groups did not focus on the group as a whole and avoided discussion of group tasks, processes, or intergroup relationships. The professionally-led groups had more risk-taking interactions, indicating that members felt comfortable enough to share their situations and confront other members. Within both types of groups, the most frequently occurring help-giving activities were behavioral prescription, normalization, encouragement of sharing and explanation. The least frequently occurring activities were requesting feedback, punishment, and extinction. Members of leaderless groups gave significantly higher ratings for encouragement of sharing, self-disclosure, establishment of group goals, assertion of group norms and mutual affirmation. According to the findings, professional leadership did not make a major difference in the verbal interactions and helping activities occurring in parent support groups. The findings also demonstrate the need for additional content about group dynamics and small group theory in social work education.