Self-injurious behaviors are a pervasive problem among prisoners. The aim of the present study was to concurrently evaluate whether emotion regulation explain association between pathological personality traits and self- injurious behavior among Iranian prisoners. The statistical population comprised all prisoners at Qezalhasar Penitentiary in Karaj during the second half of 2023. Data were collected using the adult version of the DSM-5 Personality Questionnaire, the Cognitive Emotional Regulation Questionnaire, and Klonsky and Glenn’s Inventory of Statements About Self-Injury. Based on the obtained results, there was a positive and significant relationship between self-injurious behavior and negative affectivity (β = 0.13, T = 2.29), detachment (β = 0.11, T = 2.01), antagonism (β = 0.14, T = 2.44), disinhibition (β = 0.12, T = 2.15), psychoticism (β = 0.13, T = 2.36), and negative cognitive emotion regulation (β = 0.26, T = 4.19). Additionally, a negative and significant relationship was observed with positive cognitive emotion regulation (β = –0.21, T = –3.48) (p < 0.01). It is recommended to create conditions in penal institutions to minimize the occurrence of these behaviors and the psychological disorders that contribute to them and provide psychological counseling for the prison population with a focus on emotion regulation.
