This case study explored changes in leadership behaviors and characteristics that had occurred as a result of participation in an action learning program, and explained how the program had led to such changes in leadership. The case was an action learning program that was used at a company in Korea. The findings showed that communication skills were perceived to have been most likely influenced by action learning. The other elements that had been more likely influenced by action learning included visionary, follower-centered, reward equity, caring, and confident leadership. The links between action learning and changes in leadership indicated that the activities related to the questioning and reflection component seem most likely to facilitate changes in leadership behaviors and characteristics. The findings of this study provide HRD practitioners with an insight into how an action learning program needs to be designed and operated to maximize the effectiveness of a leadership development program.