This study investigates the relationship of self-differentiation with individualism and collectivism among college students. Special focus was on whether distinctions between vertical and horizontal individualism and collectivism were more useful in examining the relationship with self-differentiation. The results reveal that different aspects of individualism and collectivism were differently related to self-differentiation, indicating that self-differentiation was negatively associated with all aspects of collectivism and with vertical individualism, but positively with horizontal individualism. This study proved that four distinct constructs were more useful in explaining the effects on self-differentiation. The implications of the findings are discussed for clinicians and future research.