This paper examines the role of sociodemographic characteristics on non-traditional mature freshmen higher education dropout rates. One of Chile's largest higher education institutions, which has an important number of mature students from more deprived social sectors, was used as a case study. A quantitative methodology was applied, based on the estimation of logistic regression models, where freshmen dropout rates were defined as the dependent variable and three types of independent variable were considered: family/demographic conditions, socio-economic situation and institutional structures. The results indicate that students who are parents, have a job, are not the heads of their households, are enrolled in longer programmes and who attended adult high school are more likely to drop out of higher education during their first year of study. Suggestions for institutional practices to better integrate mature students into higher education are discussed.