Background Mothers with borderline personality disorder face unique challenges in parenting, as borderline symptoms have been shown to negatively affect parent-child relationships. These challenges can lead to non-supportive reactions to children's negative emotions, a form of parent emotion socialization (PES) that has been linked to negative outcomes in children. Given the inherent emotional arousal evoked by parenting, emotion dysregulation likely influences the type of PES parents utilize. However, no studies have specifically examined how emotion dysregulation affects PES in mothers with borderline pathology. Against this background, this study aims to (1) investigate the link between maternal emotion dysregulation and PES strategies and (2) assess if emotion dysregulation mediates the relationship between borderline pathology and PES. Methods The study sample was comprised of 148 mothers (