We examined an at-risk population in China, money boys (MBs), to evaluate their potential role for transmitting HIV and sexually transmitted infections (STIs). Data were collected from 418 MBs selected by time-location cluster sampling, using a self-administered computerized questionnaire and testing a small blood sample for HIV/STIs. One-third (32.1%) of participants self-identified as homosexual, 25.4% heterosexual, 33.5% bisexual, and 9.1% uncertain. Consistent condom use by participants was 70-80% with commercial sex partners, 43.9% with girlfriends, and 60-70% with other non-commercial partners. HIV prevalence was 3.3%; syphilis, 10.5%; and HSV-2, 11.0%; overall prevalence for any was 20.3%. Factors significantly associated with HIV/STIs included being minority (OR = 4.82), having only male partners (OR = 1.92), having more male casual partners in the last 6 months (OR = 1.28), being younger at sexual debut (OR = 1.14), and being older (OR = 1.11). This study emphasizes the importance of developing targeted interventions for MBs, particularly those who are homosexual or minority.