Given the important contextual function of family dynamics and traditional gender roles in Latino cultures, parental influences on substance use among Latino adolescents may differ across genders. This study examined associations between family factors (parental monitoring, parent-child communication, family cohesion, and familism) and marijuana use among 1,369 Latino adolescents in Southern California. Students from seven schools completed surveys in 9th and 11th grades. Longitudinal hierarchical linear regression analyses evaluated the associations between family factors in 9th grade and lifetime marijuana use in 11th grade, as well as gender differences in these associations. Girls reported higher levels of parental monitoring, parental communication, and familism than boys did, but there were no gender differences in family cohesiveness. In a regression model controlling for covariates and previous marijuana use, parent-child communication and family cohesion in 9th grade were each uniquely predictive of lower levels of marijuana consumption in 11th grade. Gender was a statistical moderator, such that higher levels of parent-child communication predicted lower marijuana use among boys, whereas girls' use was relatively low regardless of parent-child communication levels. Results are discussed in the light of the concurrent socialization processes of family and gender in Latino culture and its relation to preventing delinquent behaviors such as marijuana use.