We investigated the overall prevalence and the differential comorbidity of Diagnostic and Statistical Manual (DSM)-III-R personality disorders in 166 remitted or recovered patients with schizophrenic (n = 102) or unipolar mood disorder (n = 64). Over 60% of both patient groups met the DSM-III-R criteria of at least one DSM-III-R personality disorder as assessed by means of the Structured Clinical Interview for DSM-III-R (SCID-II-R), receiving on average 3.1 personality diagnoses. Neither DSM-III-R categories of personality disorders, nor scores on its three clusters A, B and C, nor total score on SCID-II-R differed significantly across the two groups. In conclusion, DSM-III-R personality disorders, although highly prevalent in schizophrenic and unipolar mood disorders, lack any specificity with respect to these categories of mental disorders.