Few studies have examined the experience of chronic sleep disturbances in those with borderline personality disorder (BPD), and further establishing this association may be pertinent to enhancing current treatments, given the relevance of sleep to emotion regulation and stress management.Data were analyzed (N = 5,692) from Part II of the National Comorbidity Survey-Replication (NCS-R) sample (Kessler & Merikangas, 2004), which assessed personality disorders and sleep problems. Rates of chronic sleep disturbances (difficulty initiating sleep, difficulty maintaining sleep, and waking earlier than desired), as well as the consequences of poor sleep, were examined. Indices for BPD diagnosis and symptoms were used in logistic and linear regression analyses to predict sleep and associated problems after accounting for chronic health problems, Axis I comorbidity, suicidal ideation over the last year, and key sociodemographic variables.BPD was significantly associated with all 3 chronic sleep problems assessed, as well as with the consequences of poor sleep. The magnitude of the association between BPD and sleep problems was comparable to that for Axis I disorders traditionally associated with sleep problems. BPD symptoms interacted with chronic sleep problems to predict elevated social/emotional, cognitive, and self-care impairment.Sleep disturbances are consistently associated with BPD symptoms, as are the daytime consequences of poor sleep. There may also be a synergistic effect where BPD symptoms are aggravated by poor sleep and lead to higher levels of functional impairment. Sleep in patients with BPD should be routinely assessed, and ameliorating chronic sleep problems may enhance treatment by improving emotion regulation and implementation of therapeutic skills. (PsycINFO Database Record (c) 2013 APA, all rights reserved).