We examine the impact of an adapted community popular opinion leader (C-POL) intervention targeting alcohol-using social networks in Southeast Louisiana. A pre-post C-POL was conducted between October 2009 and April 2013, targeting alcohol users. A total of 65 popular opinion leaders were recruited, trained, and deployed into their social networks to diffuse intervention messages. Anonymous community surveys conducted within the venues among 99 male and female participants at baseline and 197 at 6 months to 1 year later revealed significant behavioral and knowledge changes. Average sexual risk score based on 7 sexual risk items declined from 15.3 to 11.9 (p<0.001); the number of vaginal and anal sex partners in the last year decreased from 11.3 to 7.7 and 3.9 to 2.3, respectively (p<0.01); and HIV knowledge score (based on % correct) increased from 67.2 to 76.8% (p<0.001). Findings add to the evidence base surrounding peer interventions.