This study examines campus organization involvement as a mechanism for social capital development. Researchers used analysis of variance (ANOVA) to examine variations in network size, strength, and composition for international students involved in different types of campus organizations. The researchers also examined the relationship of campus organization involvement to international students' sense of attachment to the university. Students who participated in major-based organizations or leadership programs had larger, less dense, more diverse networks that lead to social networks which are particularly advantageous to social mobility. Students who participated in campus organizations related to their own cultural heritage had networks built of friends from all cultures, creating a greater sense of belonging and attachment to the university. Implications of social capital for practice and future research are discussed.