Background Male sex workers (MSW) in China, known as “money boys”, have been identified as a bridging population for transmission of HIV/STIs between communities of men who have sex with men (MSM) and the general population.

Method Based on geographic mapping and enumeration results in Chengdu, a sample of sex work venues (n = 23) was selected and profiled to understand the network operation and forming of the MSW industry in Chengdu. To reduce the social desirability bias of face-to-face interviews, Polling Booth Survey (PBS) was used to document the risks behaviours of MSWs (n = 130). Data from voluntary counselling/testing (VCT) of MSW (N = 531) and general MSMs (N = 1908) were analysed for HIV prevalence.

Results On average, MSW provided sexual services to 4–6 clients (mean = 2.4 ± 3.5) per day, with as many as 10 clients (mean = 7.1 ± 5.25 std) in a peak day. All respondents reported 100% condom use during face-to-face interviews. PBS results, however, revealed that only 74% of MSW used condoms every time and 76% in last anal sex. Using condoms with permanent sex partners was lower (44% last month anal sex). 14% of MSW had anal sex 3+ times, and 4% had anal sex 7+ times in one day. VCT data showed a relatively lower HIV prevalence (6%) in MSW (N = 531) compared to the HIV prevalence (10%) in MSM in 2012. 29% of MSWs identified as heterosexual, 20% as bisexual, and 51% as gay.

Conclusion Male sex work in urban China has grown into a thriving industry. Due to high client volumes, unprotected anal sex, multiple concurrent sexual partners, and participation in sexual networks that span various cities throughout China, MSWs are at a higher risk for HIV/STI transmission. PBS is a more reliable method to examine risky sexual behaviours among high risk populations.