Drawing on cultural-ecological and person-environment fit perspectives, this study examined links among Mexican-American adolescents' time with peers and parents, parents' cultural orientations, and adolescents' psychosocial adjustment and cultural orientations. Participants were 492 Mexican-American adolescents (Ms=15.7 and 12.8 years for older siblings and younger siblings) and their parents in 246 families. Family members described their family relationships, cultural orientations, and psychosocial functioning in home interviews, and time-use data were collected during a series of nightly phone calls. Mexican-American adolescents spent the majority of their peer time with Mexican youth. Some support was found for the hypothesis that the "mismatch" between parents' cultural orientations and adolescents' peer involvement is linked to adolescents' psychosocial functioning.