The objective of this study was to investigate the personological factors underlying marijuana use in the college population. Under anonymous conditions, 148 students at two universities completed the California Psychological Inventory and a biographical questionnaire concerning drug usage. Four conclusions were reached: (1) marijuana use at two universities can be predicted with fair accuracy, (2) users and non-users are indistinguishable with regard to their secondary education, extracurricular activities, or athletic participation. They differ, however, in fraternity membership, academic major, year in school, and scholastic achievement. (3) Users show a personality pattern somewhat at variance with many stereotypes, while they are in some ways anti-social, they are characterized by valuable traits as well, and (4) the character structure of non-users is not necessarily superior to that of users. Marijuana use is perhaps more properly classified as amoral than immoral, and current disapproval of its use may reflect a cultural emphasis rather than a truly "moral" judgment. (Author/EK)