Personality, environmental, and behavioral variables representing psychosocial risk factors for adolescent problem behavior were assessed in a 1974 national sample study of over 10,000 junior and senior high school students. Significant correlations were found with marijuana use, and the relationships held across differences in age, sex, and ethnic group membership. Greater involvement in marijuana use was associated with greater value on independence than on academic achievement, lower expectations for academic achievement, lesser religiosity, greater tolerance of deviance, less compatibility between friends and parents, greater influence of friends relative to parents, greater models and support for problem behavior, greater actual involvement in other problem behaviors such as drunkenness, and less involvement in conventional behavior such as attending church. Multiple regression analyses show that this pattern of psychosocial correlates accounts for over 50 per cent of the variation in marijuana use. The pattern is nearly identical to the pattern that accounts for problem drinking in these same adolescents. The similarity of the patterns of psychosocial risk, and the substantial correlations of marijuana use with problem drinking and with other problem behaviors, suggest that marijuana use is best seen as part of a syndrome of adolescent problem behavior. (Am J Public Health 70:604- 613,1980.)