Increases in substance use prevalence among girls, as well as a lack of research conducted with urban girls of color, highlight the importance of understanding both predictors and outcomes of substance use abstinence (SUA) within this population. This study addresses gaps in SUA research through a longitudinal investigation conducted with urban black non-Latina and Latina girls (N = 597) as they transitioned through junior high school. Multivariate logistic regressions found social influences (i.e., friend/family use, drug access) to be significantly associated with girls' SUA, although differential associations were found by race/ethnicity. SUA was also associated with positive adjustment and wellness by ninth grade. Implications for gender-specific prevention programming are discussed. (Contains 4 tables.)