Results indicate that for girls, increased television viewing, low self-esteem, poor parental relationships, living in a non-intact household, higher levels of externalizing behavior, low academic achievement, and parents with low education levels were associated with earlier sexual debut. For boys, advanced pubertal development, increased television viewing, higher rates of externalizing behaviors, and poor parental relationships were associated with earlier sexual debut. This study identified factors leading to early sexual behavior, examining the role of key individual, familial and sociocultural factors that might be related to the onset of early sexual behavior. Data were collected at several ages from 273 adolescents who are part of an ongoing longitudinal study, the Wisconsin Study of Families and Work. Participants were given a battery of self-administered measures on a laptop computer. Puberty, identification with the media television viewing, depression, externalizing behaviors, and school achievement were measured at age 13. Relationship with parents, self-esteem, and sports participation were assessed at age 15. Tables and references