Studies tracking trends in HIV prevalence and risk behavior among men who have sex with men (MSM) in China are rare. We report on 3 consecutive cross-sectional surveys measuring the prevalence of HIV, other infectious diseases, and related risk behavior among MSM in Beijing in 2004, 2005, and 2006. We applied respondent-driven sampling (RDS) to recruit MSM for a structured face-to-face interview on demographic characteristics and HIV risk-related behavior. Blood specimens were drawn for HIV syphilis, hepatitis B virus, and hepatitis C virus (HCV) testing. A total of 325 MSM participated in 2004, 427 in 2005, and 540 in 2006. HIV prevalence was 0.4% (95% confidence interval [CI]: 0.1 to 0.8) in 2004, 4.6% (95% CI: 2.2 to 7.6) in 2005, and 5.8% (95% CI: 3.4 to 8.5) in 2006. This apparent rise was accompanied by an increase in syphilis and self-reported history of sexually transmitted diseases (STDs), high prevalence of multiple sex partners, and low consistent condom use. HCV prevalence also increased, from 0.4% (95% CI: 0.1 to 0.8) in 2004 to 5.2% (95% CI: 2.3 to 8.2) in 2006. We detected a possible rising prevalence of HIV and related risk behavior among MSM in Beijing using RDS in each of 3 consecutive years. Practical measures, including MSM-friendly HIV testing, STD services, and health provider education, are urgently needed to stop the further spread of HIV in this population.