The study objective was to assess the severity and quality of dissociative experiences reported by borderline patients. Two hundred ninety criteria-defined borderline patients and 72 axis II controls completed the Dissociative Experiences Scale (DES), a 28-item self-report measure with demonstrated reliability and validity. Thirty-two percent of borderline patients had a low level of dissociation, 42% a moderate level, and 26% a high level similar to that reported by patients meeting criteria for posttraumatic stress disorder (PTSD) or dissociative disorders. The controls had a significantly different distribution of overall DES scores: 71% reported a low level of dissociation, 26% reported a moderate level, and only 3% reported a high level. In addition, borderline patients had a significantly higher score than the controls on 21 of 28 DES items and a significantly higher overall DES score, as well as the score on the 3 factors that have been found to underlie the DES, absorption, amnesia, and depersonalization. The results of this study suggest that the severity of dissociation experienced by borderline patients is more heterogeneous than previously reported. They also suggest that borderline patients have a wider range of dissociative experiences than are commonly recognized, including experiences of absorption and amnesia, as well as experiences of depersonalization.