This study examined gender bias in Borderline Personality Disorder (BPD) and Antisocial Personality Disorder (ASPD) diagnosis through the review of clinical interviews and examination of the MMPI-2 clinical scale elevations rendering either diagnosis. It was hypothesized that women with MMPI-2 clinical scale elevations on Scale 4 (Psychopathic Deviant (Pd)) and Scale 8 (Schizophrenia (Sc)) would more likely be diagnosed with BPD than men with identical scale elevations. Men with MMPI-2 clinical scale elevations on scales 4 (Pd) and 8 (Sc), would more likely be diagnosed with ASPD than women with similar scale elevations. Furthermore, women in the forensic population would be more likely to be diagnosed with BPD than women in the clinical population. Finally, men would be more likely diagnosed with ASPD in the forensic population than men in the clinical population. The results indicate a statistically significant relationship between gender and diagnosis; females were significantly diagnosed with BPD more than males and males were significantly diagnosed with ASPD more than females. Furthermore, no statistically significant relationship was found between population and diagnosis; females were diagnosed with BPD about the same in the forensic and clinical population sample. Also, males were diagnosed similarly with ASPD in the forensic and clinical population sample.