Etiologic models of bulimia center on dieting and negative affect, yet no research has subtyped bulimic individuals according to whether they fit dietary versus negative affect profiles. This study subtyped 265 bulimic women along dieting and depressive dimensions and tested whether subtypes showed differences in eating pathology, clinical correlates, and treatment response. Cluster analysis revealed a pure dietary subtype (62%) and a mixed dietary-depressive subtype (38%). Whereas dietary and dietary-depressive bulimic women showed similar levels of bulimic behaviors, the latter reported more eating and weight obsessions; social maladjustment; higher rates of mood, anxiety, eating, impulse control, and personality disorders; and poorer treatment response. Results suggest dieting is a central feature of bulimia, but depressive affect occurs in only a subset of cases. However, the combination of dieting and depressive affect seems to signal a more severe variant of bulimia.