Background: Increasing public health concerns are being raised about adolescent self-harming behaviors. The previous study indicates that childhood trauma can be related to self-harm. Objectives: The study aimed to investigate the relationship between childhood trauma, cognitive flexibility, and cognitive distortions in predicting self-harming behaviors among female adolescents in Shahrood, Iran. Materials & Methods: The research method was cross-sectional. The statistical population of the study included all female students in the junior high schools of Shahrood, Iran in the academic year 2022-23. A sample of 220 female adolescents (aged 13–, 15) was recruited through multi-stage sampling. Participants had at least one self-harming behavior in their clinical records. The child Trauma Questionnaire (CTQ), Cognitive Flexibility Inventory-Iranian Version, The Cognitive Distortion Scale, and Self-Harm Behavior Questionnaire were completed. Data were analyzed using the Pearson correlation coefficient and multivariate linear regression model. Results: The mean age of study participants was 13. 70±, 1. 02, almost 73% of the samples were from 13 to 14 years old, and most students came from three-and four-member families (81%). Findings of multivariate linear regression revealed that childhood trauma (β, =0. 137, t=2. 828) and cognitive distortions (β, =0. 188, t=3. 940) were positive and significant predictors of self-harming behaviors in adolescents. Moreover, Cognitive flexibility (β, =-0. 237, t=-4. 957) was a negative and significant predictor of self-harming behaviors in adolescents. Conclusion: The results of this study may have implications for increasing mental health awareness among students and school programs to prevent self-harm.