This paper describes drug and sexual risk behaviors during a six-month period in 2001 of 2,916 gay and bisexual men who were recruited online. Bivariate and multivariate analyses examined correlates of unprotected anal intercourse (UAI). Drug and alcohol use were also examined by US region. UAI was associated with using alcohol or drugs, including poppers, crystal methamphetamine, cocaine, marijuana and Viagra before or during sex. Meeting sex partners both online and offline and having multiple sex partners were also predictive of UAI. Significant regional differences were seen in the prevalence of drug use and alcohol use. Findings are discussed in relation to the need to integrate messages about the relationship between drug use and sexual behavior into HIV prevention programs.