Background: Borderline personality disorder is one of ten personality disorders identified in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. The impairments in mentalizing capacity are a core feature of borderline personality disorder and are related to affect dysregulation and poor impulse control Aim of the study is to assess borderline personality traits and mentalizing capacity among nursing schools' students.  Design: explorative correlational design was used in the study. Setting: The present study was carried out at nursing schools at Ismailia city   Sample technique: A convenient sample technique was utilized, Subject all nursing students (512), Tools of data collection: - semi-structured interview questionnaire was divided into three  tools, tool I: demographic characteristics, tool II: borderline personality questionnaire,  tool III: - Mentalization scale, results: the mean age was (16.64 ± 0.870),  the mean of borderline personality traits was (31.72 ± 14.7) that indicate, the cutoff point of borderline personality questionnaire was (53.75). also, 11.32 % of nursing students have borderline personality traits. Additionally, there was statistically negative relation between borderline personality traits and mentalizing capacity among nursing school's students. Conclusion, 11.32 % of nursing students have borderline personality traits. Additionally, there was statistically negative relation between borderline personality traits and mentalizing capacity among nursing school's students Recommendation, developing an educational program about borderline personality manifestation and its impact on overall wellbeing of nursing students and their future nursing carrier.