Objective: To determine the extent to which personal, behavioral, and environmental factors are associated with human immunodeficiency virus/sexually transmitted infection (HIV/STI) testing and disclosure. Participants: Nine hundred thirty HIV-negative collegiate men who have sex with men (MSM) who completed an online survey about alcohol use and sexual behavior. Methods: Correlates of testing and disclosure significant in bivariate analyses (p < 0.05) were grouped into personal, behavioral, or environmental factors and entered into multivariable logistic regression models. Results: About half of participants tested for HIV (51.9%) and for STIs (45.8%) at least annually. Over half (57.8%) of participants always/almost always discussed HIV status with new sex partners; 61.1% with new unprotected sex partners. Personal and behavioral factors (age and outness) explained differences in testing, and the behavioral factor (routine testing) explained differences in disclosure. Conclusions: Collegiate MSM should be supported in coming out, encouraged to engage in routine testing, and counseled on discussing HIV/STI status with potential sex partners.