PIP: A longitudinal study examined the emotional and interpersonal processes involved in contraceptive behavior among 201 sexually active female adolescents 14-19 years of age recruited from adolescent medicine clinics in San Francisco, California (US). At study entry, adolescents completed questionnaires regarding sociodemographics, sexual and reproductive history, sexual self-acceptance, sexual communication with partners, and current contraceptive use. At a 6-month follow-up interview, participants reported on all sexual activity and contraceptive use since study enrollment. Path analysis indicated greater sexual self-acceptance was significantly related to more sexual communication and more contraceptive communication. Contraceptive communication, in turn, was associated with more frequent and more effective contraceptive use. Higher levels of contraceptive communication predicted both more frequent and more effective contraceptive use at the 6-month follow-up even when the effects of baseline contraceptive use were controlled. When the association between sexual self-acceptance and subsequent contraceptive behavior was examined apart from communication about sexuality and contraception, sexual self-acceptance directly predicted contraceptive effectiveness but not frequency. These findings underscore the importance of interpersonal processes in sexual and contraceptive behavior and suggest the utility of interventions that provide adolescents with skills for discussing contraception.