The present study examined whether personality-based subgroups of bulimic individuals differed in eating disorder behavior, comorbid psychopathology, treatment history, and momentary assessments of mood and behavior. Participants completed an Ecological Momentary Assessment (EMA) protocol for a period of 2 weeks. Latent profile analysis on the Dimensional Assessment of Personality Pathology revealed 3 groupings of bulimic participants: Interpersonal-emotional, Stimulus seeking-hostile, and Low personality pathology. The personality-based groups differed in histories of mood, anxiety, substance use disorders, features of borderline personality disorder, treatment history, and several momentary measures. These findings suggest that personality variation within the bulimia nervosa diagnostic construct may be associated with meaningful conceptual and clinical differences, including daily experiences in the natural environment.