This study investigates the importance, in adolescence, of motivational, contextual, and demographic variables in predicting professional attainment in the early stages of career development. Using a synthesis of two theories; the Levinson Life Cycle and the Astin Theory of Career Choice, longitudinal data derived from approximately 3,000 adolescent students over a 10-year period from final year secondary school through to the age of 27 was analyzed using LISREL structural equation modeling. Predictor variables were selected from the data in line with a new contextualist theoretical model of career choice that contained variable blocks or conceptual "career tracks," comprising socioeconomic background, sex role socialization, work motivation, external constraints operating on choice, and career planning. Results from the study showed that external contextual factors such as socialization influences from the family parental expectations and occupational expectations and individual factors such as ability and attainment were powerful determinants of professional attainment. Sex differences revealed that student perceived parental expectations for sons had a stronger effect on school attainment and expectations than did parental expectations for daughters. Further, the effects of constraints operating on college attainment and professional attainment were stronger for women than for men. Analyses indicated that the Astin model of career choice needs further refinement and the value of a contextualist framework is suggested.