The Expectancy Challenge Alcohol Literacy Curriculum (ECALC) is a single session group-delivered program designed to modify alcohol expectancy processes and reduce alcohol use among children and young adults. The objective of this study was to demonstrate the effectiveness of the ECALC in reducing risky alcohol use among heavy drinking college men. Four fraternities at a large state university were randomly assigned to receive either the single session ECALC or a control presentation (2 fraternity houses per condition, n=250). Alcohol expectancies were assessed before and immediately after program presentation. Results demonstrated significant changes on 5 of the 7 subscales of the Comprehensive Effects of Alcohol Scale (CEOA) among students who received the ECALC when compared with control participants. Alcohol use data were collected for 4 weeks before and 4 weeks after program presentation. Compared with those in the control condition, students who received the ECALC demonstrated significant reductions in all facets of alcohol use measured, including decreased mean and peak blood alcohol content (BAC), decreased mean number of days drinking per week, decreased mean drinks per sitting, and decreased number of binge-drinking episodes per month. This study represents 2 important advances. First is the significant reduction in risky alcohol use produced by a single session group-delivered program. The second important advance is the success in changing expectancy processes without using impractical elements common in previous expectancy challenge methods (e.g., a "barlab" environment and actual alcohol administration).