Women with Premenstrual Dysphoric Disorder (PMDD) are more likely to have a history of childhood trauma, and may experience more severe premenstrual symptomatology. However, the pathway in which childhood trauma affects the prevalence and severity of premenstrual symptoms remains largely unclear.To determine whether childhood trauma is associated with increased premenstrual symptoms, and if so, whether emotional dysregulation mediates or moderates this relationship.A total of 112 women were recruited for the study among students at the Hebrew University of Jerusalem.Participants completed the Premenstrual Symptoms Screening Tool (PSST), the Childhood Trauma Questionnaire (CTQ) and the Difficulties in Emotion Regulation Scale (DERS). To test the mediation hypothesis, direct and indirect effects of childhood trauma on premenstrual symptoms were calculated. To test moderation, we performed multiple regression, including the interaction term between childhood trauma and emotion dysregulation RESULTS: Twenty-two women (18.6%) met criteria for premenstrual syndrome (PMS) and sixteen (13.6 %) for PMDD. The number and severity of premenstrual symptoms increased with more childhood trauma (r = .282), and this relationship was completely mediated by emotion regulation difficulties. Specifically, exposure to Sexual abuse (r = .243) and Emotional neglect (r = .198) were significantly associated with premenstrual symptoms. Abuse predicted greater emotion dysregulation (r = .33), whereas, neglect did not.This study contributes to the current knowledge on the long-term effects of childhood trauma. Promoting use of adaptive emotion regulation strategies for women with a history of childhood trauma, could improve their capability to confront and adapt to premenstrual changes.