This study was designed to develop reliable and valid quantitative measures of the beliefs and attitudes toward hepatitis B virus (HBV) vaccination among gay men, using a community-based participatory research approach. A convenience sample of 358 gay men was recruited in two gay bars. Exploratory factor analysis performed on the first split-half sample was used to assess the factor structure from five scales measuring beliefs about HBV vaccination. The scales were based on constructs from the health belief model and the social cognitive theory. Confirmatory factor analysis was performed on the remaining half-sample using structural equation modeling. Multivariable analysis further validated the scales. These findings propose standardized measures that may be useful in assessing the beliefs and attitudes of gay men toward HBV vaccination to guide intervention design and evaluation.