Purpose: To assess condom application ability and the relationship between perceived ability and demonstrated ability. Also, to examine the association between high-demonstrated condom application ability and recent sexual risk behaviors and laboratory-diagnosed sexually transmitted diseases (STDs) among African-American adolescent females. Methods: A purposeful sample of sexually active African-American females (n = 522) completed a structured interview and provided vaginal swab specimens for STD testing. Subsequent to the interview, adolescents demonstrated their condom application skills using a penile model. A 9-item scale assessed adolescents' perceived self-efficacy to apply condoms. Sexual risk behaviors assessed by interview were noncondom use at last intercourse and the last five intercourse occasions for steady and casual sex partners as well as any unprotected vaginal sex in the past 30 days and the past 6 months.Results: Approximately 28% of the sample tested positive for at least one STD and nearly 26% self-reported a history of STDs. Controlled analyses indicated that adolescents' self-efficacy for correct use was not related to demonstrated skill. Adolescents' demonstrated ability was not related to any of the sexual risk behaviors. Likewise, recent experience applying condoms to a partner's penis and demonstrated ability were not related to laboratory-diagnosed STDs or self-reported STD history. Conclusions: Adolescents may unknowingly be at risk for human immunodeficiency virus and STD infection owing to incorrect condom application. Further, high-demonstrated ability to apply condoms was not related to safer sex or STDs. Reducing sexual risk behaviors may require more than enhancing adolescent females' condom application skills and may require addressing other relational skills. Copyright © 2001 Society for Adolescent Medicine.