This study examines two issues relevant to adolescents' self-reported sexual and contraceptive use behaviors: reliability of partner-referent reports versus 3 and 6 month reports, and test-retest reliability of reports completed over a 2 week period. Data are from 196 13 to 18 year old girls recruited into this study while they south reproductive care from health clinics in a metropolitan area. All participants reported having had sexual intercourse during the past 6 months. Twice over a 2 week interval, participants completed the same paper and pencil surveys. The survey presented questions about sexual behavior and contraceptive use using 3 sequential frames of reference: within the past 6 months, within the past 3 months, and by specific sexual partners in the past 6 months. Findings demonstrate that adolescent girls can reliably report sexual behavior and contraceptive use over a 6 month interval. Study findings have implications for future research utilizing adolescents' self-reported sexual and contraceptive use behaviors.