Neighborhood characteristics have been shown to impact child well-being. However, it remains unclear how these factors combine with family characteristics to influence child development. The current study helps develop that understanding by investigating how neighborhoods directly impact child and adolescent behavior problems as well as moderate the influence of family characteristics on behavior. Using multilevel linear models, we examined the relationship among neighborhood conditions (poverty and social capital) and maternal depression on child and adolescent behavior problems. The sample included 741 children, age 5–11, and 564 adolescents, age 12–17. Outcomes were internalizing (e.g. anxious/depressed) and externalizing (e.g. aggressive/hyperactive) behavior problems. Neighborhood poverty and maternal depression were both positively associated with behavior problems for children and adolescents. However, while neighborhood social capital was not directly associated with behavior problems, the interaction of social capital and maternal depression was significantly related to behavior problems for adolescents. This interaction showed that living in neighborhoods with higher levels of social capital attenuated the relationship between maternal depression and adolescent behavior problems and confirmed the expectation that raising healthy well-adjusted children depends not only on the family, but also the context in which the family lives.