This study examined the determinants of international students' interactions with different friendship networks and the relationships of these interactions with study abroad outcomes, using data from 482 Korean college students who had participated in international student exchange programs. The results showed that students' participation in extracurricular and off-campus activities while studying abroad was significantly related to their interactions with local and other international students. The results also showed that students' interactions with co-national, local, and other international students while studying abroad were positively associated with their intercultural competence, personal development, and career development, even after controlling for other variables. We discuss the policy implications of these findings beyond the Korean context.