Acculturative stress is viewed as detrimental to the mental health and prosocial behaviors of Latinx young adults, but empirical research on the topic is scarce. The present study examined the intervening role of internalizing symptoms in associations between acculturative stress and prosocial behaviors in Latinx college students. Participants included 1410 (74.9% women; M age = 19.71 years; 77.5% U.S.-born) Latinx college students, who reported on their levels of acculturative stress, internalizing symptoms, and public, and altruistic prosocial behaviors. Path analyses showed that acculturative stress was directly and indirectly related to public and altruistic prosocial behaviors via internalizing symptoms. Moreover, these associations varied by nativity (U.S.-born vs. foreign-born status) of participants. Our findings highlight the mental health strain on prosocial behaviors in the context of acculturative stress. Discussion focuses on the importance of studying within-group (e.g., nativity) differences in Latinx college students’ acculturative stress and adjustment. Implications for theory and intervention work for Latinx positive development are presented. (PsycInfo Database Record (c) 2021 APA, all rights reserved)