The concurrent validity of the Beck Depression Inventory (BDI) was evaluated in 122 outpatient adolescents referred to a clinic for depression. Criterion validators were Kiddie-Schedule for Affective Disorders and Schizophrenia (K-SADS) generated diagnoses and a 17-item clinician-rated depression scale extracted from the K-SADS. Initial BDI scores of greater than 13 yielded sensitivity, specificity, and positive predictive powers of 86%, 82%, and 83%, respectively, in differentiating syndromal major depressive disorder (MDD) from nonaffective disordered patients. In repeated interviews in 2 weeks with a BDI score of greater than 13, these parameters were 89%, 88%, and 93%, respectively, in those meeting MDD criteria. The BDI correlated significantly with the 17-item depression score in depressed females but not depressed males because BDI scores were more than 30% higher in females. BDI internal consistency among all cases was 0.91 and was higher in depressed than nondepressed patients.