The Information-Motivation-Behavioral Skills (IMB) model of health behavior was tested in a sample of 391 men who have sex with men at high-risk for HIV transmission. Prospective analyses of IMB predictors of unprotected anal intercourse (UAI) confirmed a good fit. Self-rated motivation was a significant predictor of UAI, as were behavioral skills. However, the lack of information and motivational constructs that predicted behavior suggests that the IMB model is limited as a theory and has its greatest utility as a framework for guiding HIV risk reduction interventions for men who have sex with men at high-risk for HIV infection.