To compare self-report to interview assessment of bulimic behaviors among adolescents. A sample of children in an ongoing study were recruited to complete in-depth telephone interviews in 1998 on bulimic behaviors (i.e., binge eating and purging). The sample comprised 449 girls and 50 boys. There was some over-reporting of bulimic behaviors on the 1998 questionnaire (asking about 1997-1998) compared with the interview that may have been due to the shorter and nonoverlapping time frame in the interview compared with the questionnaire. Despite the overestimation, the questionnaire did an excellent job at classifying girls who did not purge (negative predictive values [NPV]: 0.99) or binge eat (NPV = 0.98). When purging on the interview was compared with purging on either the 1998 or 1999 questionnaires, the sensitivity increased substantially from 0.73 to 0.93. These findings suggest that a short self-report assessment can be used to screen children engaging in, or at risk of beginning to engage in, binge eating and purging. Copyright 2003 by Wiley Periodicals, Inc. Int J Eat Disord 35: 86-92, 2004.