The Russian federation has been undergoing a concentrated epidemic of HIV-1 with high rates of infection among injecting drug users. Less is known about the relative risk and contribution to the country's HIV epidemic by other at-risk populations including sex workers and men who have sex with men. The goals of this project were to explore demographic characteristics, substance use patterns, and estimate the prevalence of sexually transmitted infections (STIs) and high-risk behaviors among male sex workers (MSW) in Moscow and to assess the feasibility of prospective cohort recruitment and retention among this population. Research design was a longitudinal study of 50 men with a six-month follow-up period. Participants were recruited through venue-based and snowball sampling methods. Results revealed an HIV prevalence at baseline of 16%; one MSW seroconverted during the follow-up period, yielding an incidence estimate of 4.8/100PY (95%CI 0.0-11.2). Twenty-four percentage were diagnosed with at least one STI: 12% had syphilis; 8% had Human Papilloma Virus (HPV); and 4% had Herpes Simplex Virus (HSV)-2. Three (6%) of the study participants had evidence of previous Hepatitis C Virus (HCV) exposure at baseline. Retention rates were poor with higher retention significantly associated with older men (OR: 13.1, 95% CI 3.3-52.5). This was the first study to evaluate baseline demographics, substance use patterns, and prevalence of infectious disease among MSW in Moscow. Identification and recruitment of this population appears to be feasible, but retention a challenge. While the sample size in the current study was small, the results also suggested that this is a population at considerable high risk for HIV. MSW in Moscow may be an important at-risk population in the Russian HIV epidemic and further research is urgently required to address their needs and explore prevention strategies.