Psychological trauma can have devastating consequences on emotion regulatory capacities and lead to dissociative processes that provide subjective detachment from overwhelming emotional experience during and in the aftermath of trauma. Dissociation is a complex phenomenon that comprises a host of symptoms and factors, including depersonalization, derealization, time distortion, dissociative flashbacks, and alterations in the perception of the self. Dissociation occurs in up to two thirds of patients with borderline personality disorder (BPD). The neurobiology of traumatic dissociation has demonstrated a heterogeneity in posttraumatic stress symptoms that, over time, can result in different types of dysregulated emotional states. This review links the concepts of trauma and dissociation to BPD by illustrating different forms of emotional dysregulation and their clinical relevance to patients with BPD.