Based on an attributional model of achievement-related behavior, it was predicted that success on the part of a young person and failure on the part of an old person, being expected outcomes, would be attributed to stable causes, whereas success on the part of an old person and failure on the part of a young person, being unexpected outcomes, would be attributed to unstable causes. Using a between-subjects experimental design, subjects were asked to estimate the probability that a young vs an old stimulus person would succeed in college and to judge the causes for his success or failure. Although there occurred no differences as a function of age in expectancy of success or attributions for success, failure on the part of the old stimulus person was attributed more to the stable causes of lack of ability and task difficulty, while failure on the part of the young stimulus person was attributed more to the unstable cause of lack of effort. The results were discussed in terms of those conditions under which negative stereotypes concerning the competency of the elderly will be considered appropriate and thereby exert an influence on evaluations.