Background.The objective was to investigate the relationships between overcrowding, domestic violence, and antisocial behaviour in a sample of adolescents in Lagos metropolitan area, Nigeria. Possible gender differences and differences due to religious affiliation concerning domestic violence and antisocial behaviour were also investigated.Method.A questionnaire was filled in by 238 Nigerian adolescents, 12–20 years of age; the sample included 122 females (m = 15.1 years, s.d. = 2.0) and 116 males (m = 15.8 years, s.d. = 2.0). The respondents were from junior and senior secondary schools in Ejigbo and surrounding cities (Isolo, Egbe and Ago-Palace Lagos). Six scales were included: adolescents as victims of adult and sibling aggression, respectively, witnessing of domestic violence, parental negativity towards adolescents, antisocial behaviour among adolescents and poverty in the home. Overcrowding, gender and religious affiliation served as independent variables.Results.According to a multivariate analysis of variance with level of poverty as covariate, overcrowding showed significant associations with four of five scales measuring aggressive and antisocial behaviours. Gender and religion were associated with three variables each. However, multiple regression analyses revealed that overcrowding tended to partial out the effects of both gender and religion showing that overcrowding was the most important factor determining negative outcomes.Conclusions.The results have implications for housing policies in Nigeria. Moreover, these results may also have implications for research and policy making in other nations and parts of the world.