BackgroundRecreational drug use (RDU) may result in sexual disinhibition and higher risk for HIV and other sexually transmitted infections (STIs) among men who have sex with men (MSM) in China. We assessed whether RDU was associated with HIV, syphilis, and herpes simplex virus type 2 (HSV-2) within the context of multiple sexual partnerships and unprotected sex.MethodsWe conducted a cross-sectional study among sexually-active MSM in six Chinese cities (Kunming, Jinan, Changsha, Zhengzhou, Nanjing, and Shanghai) in 2012¿2013. We interviewed participants regarding RDU and sexual activity and drew blood for HIV, syphilis, and HSV-2. We fit multiple logistic regression models to assess associations of drug use and HIV, syphilis and HSV-2 infections, controlling for number of sexual partners and unprotected sex.ResultsOf 3830 participants, 28% reported ever using ¿1 of these drugs in the past 6 months: popper (alkyl nitrites), ecstasy, ice (methamphetamine), amphetamine, tramadol, and ketamine. In the past six months, 62% of MSM reported ¿2 sexual partners and 76% did not use condoms at last sexual encounter. HIV, syphilis and HSV-2 prevalences were 9.2%, 12.2%, and 10.3%, respectively.RDU was associated with HIV infection (aOR¿=¿1.67; 95% CI, 1.31-2.13). Men with RDU were more likely to report multiple sexual partners (OR¿=¿1.69; 95% CI, 1.44-1.98) and unprotected sex (aOR¿=¿1.25; 95% CI, 1.05-1.49). The RDU-HIV association persisted (aOR¿=¿1.58; 95% CI¿=¿1.23-2.02) after adjusting for numbers of partners.ConclusionsRDU was associated with multiple sexual partnerships, unprotected sex, and HIV among Chinese MSM. It is plausible that RDU is a driver of increased sexual/HIV risk and/or may be an associated behavior with sexually risky lifestyles. Community engagement is needed.