In this study, we examined the structural relationships among constructs from the Health Belief Model as they relate to human papillomavirus vaccine intentions in young gay and bisexual men in the United States (N = 183). A model was identified that fit the data well and accounted for 56% of the variance in vaccine intentions. Perceived benefits and barriers were the most proximate predictors of intentions, whereas knowledge and perceived threat exerted only indirect influence. Clarifying the propositional structures within the Health Belief Model can help to advance our understanding of human papillomavirus–related cognitions and behaviors and inform vaccine promotion programs.