SummaryThis article focuses on the use of alcohol and marijuana in the context of sexual relationships and the impact of these substances on the consistency of condom use by urban, minority youth. Regression models are presented to test for the effects of alcohol and marijuana use with sexual partners while controlling for the effects of respondents' sexual history. The results indicated that when alcohol or marijuana was used with a partner, the consistency of condom use decreased even when other variables related to sexual history were controlled for. Alcohol use had a greater negative effect on condom use for Hispanic men and marijuana for African-American women than it did for Hispanic women and African-American men. These findings argue for the need for targeted safer-sex intervention programs for urban, low-income, minority youth, and suggest that such programs may need to emphasize the increased risk of human immunodeficiency virus exposure that may result from substance use, casual sex, and sex with multiple partners.