CONTEXT: Russia is experiencing an explosive HIV epidemic, and young people aged 15-29 have the highest incidence of infection. Understanding factors associated with condom use in this age-group is important in developing effective prevention interventions. METHODS: Telephone interviews were conducted with 1,203 Muscovites aged 15-29 in September 2002 to assess condom use, HIV knowledge and sexual behavior. Multivariate logistic regression was used to determine independent predictors of consistent condom use. RESULTS: Forty-four percent of sexually experienced respondents reported using condoms consistently. In multivariate analysis, the likelihood of consistent use was elevated among single women and men (odds ratios, 1.8 and 2.6, respectively), those who considered condoms reliable protection against unwanted pregnancy (2.4 and 1.6) and those who believed that most of their peers use condoms (2.9 and 4.6). For women, having recently had multiple partners was associated with increased odds of consistent use, and consistent use declined with age. CONCLUSIONS: Strategies to promote condom use should increase awareness about their effectiveness against not only unwanted pregnancies but also HIV and other STDs. Condoms should be recommended for married couples and people with one permanent partner as a contraceptive option as well as for disease prevention.