The study investigated the effect of international student teaching experience on the professional and personal development of preservice teachers. Within the framework of their internship program, 26 graduate students in a private university in Turkey had a two-month internship in a mid western state in the United States, the main component of which was a six-week student teaching experience in high schools. Student teachers worked with mentors in pairs or triads in six high schools in different subject areas. They got involved in teaching practices, technology seminars, and diverse cultural activities during their internship. The student teachers and mentor teachers were surveyed through e-mail and three student teachers were interviewed to evaluate the outcomes of the program. The findings of the current research suggest that the international student teaching experience and the overall internship program with its cultural components contributed in a positive way to student teachers' professional and personal development and helped student teachers increase their cultural awareness. The findings also suggest that the presence of international students in US schools and society in general helped American students and people have a better idea of other countries and cultures. (Contains 1 figure and 5 tables.)