To effectively educate medical teachers for clerkship and residency training, the international faculty development program was developed. Ten faculties of the School of Medicine participated in the program and learned about clinical education through lectures and direct observations, transforming their educational perspectives. Factors to optimize such an international faculty development program were discussed: 1) Authentic educational institution and environment, 2) matching the participants' specialty and subject at the observation site, 3) optimal combination of lectures, direct observations, and debriefing sessions, 4) mutual understanding of cultural differences, and 5) sense of community cultivated by experiencing the program for a week. Those factors suggest ways for further improvement to reform the program, promote better management, and conduct educational research on faculty development.