Increased tolerance to alcohol is considered a risk factor for developing future problems. While college students are considered a high-risk population in relation to alcohol use it is suggested that tolerance operates differently in this population than in chronic drinking samples. Individuals' perceptions about their level of tolerance measured by social cues and comparisons to peers may influence drinking behavior. The present study evaluated the Social Tolerance Index (STI), a measure designed to examine perceptions about personal tolerance to alcohol using social cues in college students. College students (n = 177) completed measures of social tolerance, social desirability, drinking rates, and demographic information at baseline, 2-week, and 4-week follow-up assessments to assess test-retest reliability. A confirmatory factor analysis was conducted on the STI. In addition, tests of discriminant, construct and predictive validities were also conducted. The STI demonstrated good reliability and validity for use in a college student population.