The present study examines whether transformational leadership is associated with clan culture, affective commitment, and organizational citizenship behavior and whether affective commitment is positively related to organizational citizenship behavior. The study also examines whether affective commitment mediates the effects of clan culture on organizational citizenship behavior and whether clan culture mediates the effects of transformational leadership on affective commitment. The results of this study indicate a positive relationship between transformational leadership and clan culture as well as between transformational leadership and affective commitment; no significant relationship between clan culture and organizational citizenship behavior as well as between transformational leadership and organizational citizenship behavior; and a significant positive relationship between affective commitment and organizational citizenship behavior as well as between clan culture and affective commitment . Thus, the results clearly show that affective commitment fully mediates the relationship between clan culture and organizational citizenship behavior and that clan culture partially mediates the relationship between transformational leadership and affective commitment. Theoretical and practical implications of these findings as well as interesting avenues for future research are discussed. [