Distinguishing between gay venues may provide important information to better understand patterns of environmental influence and HIV/STI behavioral risk among MSM. Massachusetts MSM accessing State Health Department mobile van services (n = 214) at Gay Pride events, bars/clubs, and private safer sex parties completed a one-time, cross-sectional survey via ACASI. In the past 12 months, private safer sex party attendees reported a higher mean number of anonymous partners, were more likely to report meeting sex partners via the Internet, and were more likely to report sex while drunk; in logistic regression analyses, they were less likely to report both unprotected insertive and receptive anal sex in the past year relative to men from other venues. Private safer sex parties may represent a strategy used by some MSM to reduce HIV/STI risk. Differentiating risk behavior by venue type provides valuable information with which to effectively target interventions to reach MSM at greatest risk.