Based on a psyschosocial developmental framework, this study used a mixed model design, including both quantitative and qualitative methods, to examine the relationship between adolescents' psychosocial maturity and their alcohol use. A sample of 1,198 10th-grade students (51% female) was surveyed and followed up two years later. Both concurrent and longitudinal findings indicated that the more psychosocially mature adolescents were less likely to drink heavily than those who showed less maturity. At age 15 this relationship was even stronger for those whose peers also drank. Further, at age 17, this linear relationship was more pronounced for those who drank less heavily at age 15. Of the three psychosocial competencies examined, the construct of personal meaning was more strongly related to adolescent alcohol use than were the constructs of interpersonal understanding and interpersonal skills. To illustrate this construct, two of the adolescents were interviewed, a girl and a boy, individually at the end of both school years. Thematic and developmental analyses of the interviews revealed individual variations in how the adolescents made meaning of their drinking; these encourage speculations that go beyond the general pattern found in the study.