OBJECTIVE To present current data on bone mineral density (BMD) in adolescent women using the long-acting contraceptive depot medroxyprogesterone acetate (DMPA) and also to discuss the importance of developing maximal bone mass during adolescence to offset bone demineralization later in life. METHODS Research-based articles in the medical literature, review articles, and recommendations from the American Academy of Pediatrics and the National Osteoporosis Foundation. CONCLUSIONS Osteoporosis is a preventable disease that affects millions of Americans, particularly older women. Factors influencing the attainment and maintenance of peak bone mass during childhood and adolescence affect the future risk of fractures. Although longitudinal studies conducted on adolescent women using DMPA are very limited, findings suggest that adolescents are losing bone density during a time of expected bone accretion. CONCLUSIONS Clinicians must consider all the risks and benefits when prescribing contraceptives to adolescents. By themselves, the findings related to BMD and DMPA use by adolescents are not sufficient to limit the use of DMPA as a contraceptive method. However, clinicians must take into account the addition of other modifying factors associated with BMD that may contribute to overall bone loss in adolescent females. More prospective data on the long-term use of DMPA by adolescents are needed to determine DMPA's effect on bone loss and to determine if bone loss is transient in adolescents.