An intriguing question in modern psychopathology is the relationship of borderline syndrome disorders to other psychopathological conditions and to each other. The present study compared groups of DSM‐III defined Borderline Personality Disorder (N = 51), Schizotypal Personality Disorder (N = 14), and Mixed Borderline‐Schizotypal Personality Disorder (N = 17), with CATEGO diagnosed Schizophrenic Disorder of recent onset (N = 30) and nonpsychiatric controls (N = 20) on the MMPI. Profile and individual scale analyses revealed gross elevations on multiple scales in each of the patient groups, as compared with controls. Subtle differences in test performance between the borderline personality and schizotypal personality groups are noted and are consistent with their separation as disorders in DSM‐III. Multivariate profile analyses distinguished the borderline, schizotypal, and early schizophrenic groups from each other, but not from the mixed personality group. Thus, this latter group may serve to bridge these diverse populations.