This study examined how the link between neighborhood poverty and the timing of sexual initiation varies as a function of age, gender, and background characteristics. A sample of N = 2,596 predominately White Canadian adolescents from the National Longitudinal Survey of Children and Youth was used. Sexual initiations occurring between 12 and 15 years old were considered. Results showed that younger adolescent females who lived in poor neighborhoods and who had a history of conduct problems were more likely to report early sexual activity. Peer characteristics partly accounted for this susceptibility. Among adolescent males, no direct neighborhood effects were found, but those who had combined risks at multiple levels appeared more vulnerable. The theoretical and practical implications of these findings are discussed.