Secure parental attachment and healthy levels of separation-individuation have been consistently linked to greater college student adjustment. The present study proposes that the relation between parental attachment and college adjustment is mediated by healthy separation-individuation. The authors gathered data on maternal and paternal attachment, separation-individuation, and 3 dimensions of college adjustment in a sample of 404 college students. Using structural equation modeling, results supported a model in which separation-individuation fully mediated the link between attachment and college adjustment, for both men and women. Implications of these results are discussed for individuation-within-relatedness models of adolescent development and for counseling college students in distress.