This research study, of type quantitative, descriptive and correlational was performed on Health Center “Victor Larco”, on Victor Larco District - 2011, in order to determine the relationship between biosocioculturals factors: sex, family structure, family functioning and social skills with age of onset of intercourse among adolescents. The sample universe was consisted of adolescents old who met the inclusion criteria of the investigation. For data collection was used the instrument: Factors associated with age at first intercourse in the teenager. The information obtained was processed in SPSS 15.0 version and analyzed by statistical test "chi square". The results are presented in tables of simple and double-entry, after analysis was obtained the following conclusions: 1. Of all the adolescents in the study, 54 percent are male, 52 percent have a nuclear family, 36 percent have a g...