In modern society, companies are in a very dynamic and unpredictable environment, especially small and medium-sized companies are facing an environment of instability, changeability, unpredictability, and complexity in poor conditions compared to large companies. Companies need effective leadership to secure organizational competitiveness and to grow and satisfy individual members. Recently, the importance of transformational leadership has been emphasized for organizational members' job commitment and performance creation. Transformational leadership is highly related to enhancing the adaptability of members in change and unpredictable environments, and it has been identified as a major leadership that causes innovation-oriented and change-seeking behaviors such as contextual performance, creativity and organizational citizenship behavior, along with supervisor satisfaction, job satisfaction, commitment, and job performance. However, there is a lack of empirical research on the relationship between transformational leadership and adaptive performance. In addition, most of the studies on transformational leadership have focused on core leaders at the group level or team leaders of large organizations, and only a few have studied leadership for small and medium organizations. In a rapidly changing environment, it is necessary to study the theoretical and practical contributions of the transformational leadership that have been proven so far to be effectively introduced and applied in the management field of SMEs.