Objective: The authors identified the principal components of bar and nightclub expectancy in college students and the associations between these factors and the risk behavior of nightclubbing. Participants: A total of 4,384 undergraduates enrolled at a large, public university participated. Methods: In the first phase (July-September 2007), the authors collected preliminary data from a convenience sample. In the second phase (March 2008), the authors collected data from a separate probability sample. Results: A principal components analysis revealed 4 reliable and distinct expectancy factors. Regression analyses revealed that after adjusting for the effects of alcohol and demographic variables, expectancies explained a significant proportion of variance in bar/nightclub attendance. Different expectancy profiles distinguished high-frequency nightclubbers from the most common bar attendance practice and nonmonogamous nightclubbers from monogamous nightclubbers. Conclusions: From a developmental perspective, nightclubbing appears to assist young adults with establishing and maintaining social networks, romantic and sexual relationships, and collegiate acculturation. (Contains 4 tables.)