Longitudinal data were obtained from a nonclinical sample of 1,308 male and female adolescents covering the age range from 12 to 21. Factor analyses of 52 symptoms and/or consequences of alcohol use yielded three problem dimensions. In addition, a unidimensional, 23-item scale (the Rutgers Alcohol Problem Index, RAPI) was constructed with an internal consistency of .92. Correlations between RAPI and alcohol-use intensity were moderately strong for all age groups at each test occasion (ranging from .20 to .57), yet low enough to suggest that identification of problem drinkers requires both types of measures. The results suggest that the RAPI may be a useful tool for the standardized and efficient assessment of problem drinking during adolescence.