The role of loneliness, irrational beliefs, and deficient reasons for living in predicting vulnerability to hopelessness under conditions of negative life stress was examined. Subjects (N = 178) completed the UCLA Loneliness Scale. Rational Beliefs Inventory, and the Reasons for Living Inventory at the beginning of the semester. Then, at midterm, measures of negative life stress, depression, and hopelessness were obtained from the same subjects. It was hypothesized that the vulnerability factors would interact with negative life stress to predict hopelessness, independent of depressed mood. The results of multiple regression analyses supported this hypothesis. Implications for research, prevention, and treatment are noted.