This 1-year longitudinal study investigated the effects of adolescents' depressed mood on perceived parental and peer warmth during the transition to young adulthood. We hypothesized that ethnicity would moderate such effects. As part of a larger study, 511 adolescents (154 European, 205 Hispanic, and 152 Asian Americans) participated in this research. They were surveyed shortly before their high school graduation and again 1 year later. Analyses based on 2-wave cross-lagged models showed that higher levels of initial depressive symptoms predicted lower levels of subsequent perceived parental and peer warmth for European Americans. For Asian Americans, higher initial depressed mood was significantly associated with lower levels of perceived peer warmth and was marginally associated with lower levels of parental warmth. In contrast, the erosion of parental and peer warmth was not evident for Hispanic Americans. The role of culture in the erosion of parental and peer warmth during life transitions was discussed. © 2009, Society for Research on Adolescence.