The records of 76 bipolar (DSM-III) patients were reviewed for a history of previous misdiagnosis of schizophrenia. Multivariate analyses identified three variables significantly associated with previous misdiagnosis--auditory hallucinations, early age at onset, and ethnicity. Ethnicity remained significantly associated with misdiagnosis of bipolar patients as schizophrenic even after all other significant variables were partialled out of the equation. It appears from these data that black and Hispanic (Puerto Rican) bipolar patients may be at a higher risk than whites for misdiagnosis as schizophrenic, particularly if they are young and experience auditory hallucinations during affective episodes.