A six-month prospective study examined consistency of condom use for disease prevention among 308 adolescent women who had received a prescription for oral contraceptives at a family planning clinic. Only 16 percent used condoms consistently over a six-month period, yet 30 percent were considered at high risk for sexually transmitted diseases (STDs) because of multiple, sequential or concurrent relationships with male partners. The type of relationship in which the adolescents were involved did not predict consistency of condom use. Consistent condom use was associated with having asked a partner to use a condom, perceiving partner support for condom use, having less frequent sexual intercourse and using oral contraceptives inconsistently. The findings suggest that family planning providers need to more strongly emphasize to adolescents the importance of consistent condom use to protect against STD infection.