OBJECTIVE The purpose of this study was to prospectively evaluate the continuation rate of subdermal contraceptive implants (Norplant) among adolescent (< 20 years) and adult (> or = 20 years) women in the clinic population of a tertiary care medical center. METHODS Adolescents and adults desiring contraception for greater than a 6-month period were eligible for Norplant insertion. Prior to insertion, personal counseling and extensive education were provided. Following insertion, rapid access, personal counseling, and prompt treatment were provided for complications that occurred. Device removal was available to all individuals at any time upon patient request or if side effects could not be ameliorated. Patient demographic, historical, physical, and follow-up data were entered into a computer data base. RESULTS Since February 1991, 1800 subdermal contraceptive implants were inserted. Of these 1688 patients were prospectively followed, providing 45,576 women-months of data for analysis. Adolescents comprised 40% of the study population. Over a 50-month period, the cumulative continuation rate for adolescents was 93.6%, and for adults it was 91.1%. The mean duration of use among adolescents was 26.5 months and for adults was 27.6 months. CONCLUSIONS There was no significant difference between adolescent and adult subdermal contraceptive implant continuation rates for up to 50 months of use. In this patient population, high continuation rates may result from a combination of extensive patient education and intensive surveillance by a well-trained and dedicated multidisciplinary staff. When all patients are enrolled in a program that provides aggressive education and supportive follow-up, age is not a significant factor in continuation rates.