As research started to differentiate Nonsuicidal Self Injury (NSSI) from suicidal behaviors and to recognize it beyond being merely a symptom of specific diagnoses or a result of trauma histories, NSSI is now seen as a distinct clinical phenomenon. In line with this changing perspective in the literature, examining NSSI by reviewing its relationship with personality organization, which offers a transdiagnostic approach, and with perceived parental attitudes that shape how individuals experience adverse events may provide more in-depth insights into understanding the functions of NSSI. For this purpose, a total of 194 participants aged between 25 and 40, reporting no history of suicide attempts, were recruited via online platforms. Data were collected using a sociodemographic information form, the EMBU (My Memories of Upbringing) scale, the Inventory of Personality Organization (IPO), and the Inventory of Statements About Self-Injury (ISAS). Hierarchical Multiple Regression Analysis revealed that both personality organization and perceived maternal overprotection significantly predicted NSSI functions, whereas perceived paternal overprotection and perceived parental rejection did not. Among the significant predictors, personality organization emerged as the strongest predictor. Findings regarding the relationship between personality organization and NSSI are expected to provide valuable insights for therapists in understanding NSSI. These insights may support the development of tailored therapeutic frameworks and enhance interventions by addressing the subdimensions of personality organization, such as primitive defenses, identity diffusion and reality testing. Additionally, the relationship between maternal overprotection and NSSI demonstrates that overprotective parenting is also associated with adverse behavioral outcomes, even though it is considered less extreme than rejective parenting. The finding also emphasizes the importance of mental health-family relationship. Supporting parents by providing psychoeducation on parenting attitudes and their impact, as part of a family-centered protective and preventive mental health initiatives, is considered to be beneficial when targeting NSSI.