OBJECTIVE: Reported cases of multiple personality disorder have increased dramatically in the last decade. Few data are available on the treatment of multiple personality disorder. Current recommendations are based on the experience of individual clinicians rather than on systematic research. METHOD: A questionnaire study of 305 clinicians representing a spectrum of mental health professionals was conducted to survey the types and relative efficacy of treatment modalities currently used with cases of multiple personality disorder. RESULTS: Individual psychotherapy facilitated by hypnosis was uniformly endorsed as the primary treatment by all practitioner groups. The average patient was in twice-weekly psychotherapy facilitated by hypnosis for 3.8 years. Antidepressant and anxiolytic medications were reported to be moderately useful adjunctive treatments. CONCLUSIONS: These findings support current impressionistic treatment recommendations for multiple personality disorder regarding the primacy of psychotherapy and the moderate benefits of psychopharmacology with antidepressant and antianxiety agents.