Given the alarmingly high HIV and sexually transmitted infection (STI) incidence among gay and bisexual men (GBM) worldwide, there is a critical need for HIV prevention interventions specifically for GBM. Social anxiety, or anxiety about being evaluated in interpersonal situations, is a risk factor for condomless anal sex (CAS) among GBM (e.g., Hart & Heimberg, 2005; Hart, James, Purcell, & Farber, 2008). Social anxiety may also increase substance use in sexual situations, which is another risk factor for HIV/STIs in this risk group (Semple, Strathdee, Zians, McQuaid, & Patterson, 2011). The goal of the Sexual Confidence Study was to provide initial evidence of efficacy for a 10-session integrated cognitive-behavioral therapy for social anxiety, substance use management in sexual situations, and HIV sexual risk reduction for HIV-negative GBM. Diagnostic and self-report assessments were completed at baseline, posttreatment, 3-month follow-up, and 6-month follow-up. In this open trial design, we observed a 50% reduction in engagement in HIV/STI sexual risk behavior at 6-month follow-up. We also observed large uncontrolled treatment effect sizes for reductions in social anxiety disorder and problematic alcohol use. These preliminary findings suggest that the present treatment may offer an efficient way of concurrently reducing social anxiety, problematic alcohol use, and the risk of contracting HIV and STIs via CAS with serodiscordant partners among HIV-negative GBM.