The Brazilian government has adopted measures that aim to influence students' spatial mobility. The extent and success of such measures require detailed knowledge of the mobility determinants. Gravity models are the appropriate tool for analyzing the flows of college students from their place of origin to their destination. To analyze the determinants of student flows, we estimate a negative binomial regression model with Brazilian data. The results show the deterrence effect of distance on mobility, as the total costs of entering a university increase with the distance between the place of origin and the destination institution. Places with lower living costs and smaller university centers (campuses) are attraction factors to students, as are the possibility of having non-reimbursable financing and a larger number of study programs.