One of the DSM-III-R criteria for bulimia nervosa is a minimum binge frequency of twice a week for 3 months. We classified eating disorder patients according to different binge eating and purging frequencies and examined their concurrent and predictive validity. Frequency of purging, but not binge eating, was related to general measures of psychopathology. Neither was related to posttreatment outcome. High SCL-90 scores at pretreatment were associated with poor outcome.