Object: Personality disorders and biological personality characteristics are important factors in incidence and continuation of criminal behavior. The objective of this research was to examine the role of brain-behavioral systems in personality disorders of prisoners in Ahar, Mianeh and Maraghe.

Method: The method of study was analytical-descriptive. The subjects included 250 volunteer prisoners of Ahar, Maraghe and Mianeh Perisons, during the first 6 month of the year of 1394 selected with available sampling and completed the questionnaire of Behavioral Activation and Behavioral Inhibition System and Millon's clinical multiaxial inventory. One hundred subjects with cluster B and C personality disorders were selected. The data were analyzed with regression analysis and Pearson correlation test.

Findings: Pearson correlation analysis indicates that behavioral activation system positively and behavioral inhibition system negatively correlated with cluster B disorder. also behavioral activation system (BAS) negatively and behavioral inhibition system (BIS) positively correlated with cluster C personality disorder, while BAS positively and BIS negatively predicted cluster B of personality disorder. BAS negatively and BIS positively predicted cluster C of personality disorder.

Conclusion: The role of brain-behavioral systems and personality disorders in criminal behaviors were discussed.