The present study provides a meta-analytic review of the association between alcohol use and engagement in casual sexual relationships and experiences (CSREs). Specifically, the meta-analysis focused on non-experimental studies of community and college samples. Results from the meta-analysis, which included 29 relevant studies (34 effect sizes), indicated that alcohol use was significantly associated with engaging in CSREs, r = .34, 95 % CI [.29-.38], but that this link showed considerable variability. Subsequent analyses examined moderators that may explain this heterogeneity. Results revealed that age and method of assessment significantly moderated the effect of alcohol use on CSRE engagement such that the association was greater for emerging adults (18-24 year olds) than older adults and online assessments produced greater effect sizes than paper-and-pencil assessments. These results have implications for future research and intervention development. In particular, this meta-analysis emphasizes the need for studies that utilize consistent measurements of CSRE engagement, include diverse methodology, and expand upon sampling.