Borderline personality disorder (BPD) is a disorder characterized by emotion regulation (ER) difficulties. Although research indicates that patterns of ER differ across racial groups, few studies have examined the role of race in the ER-BPD association. This study sought to address this gap. Participants in this study identified as either East Asian, White, or Black, and were recruited from sites in Western Canada and the Southern United States. Two samples were included in this study: (a) 194 university students who self-reported BPD features and (b) 88 adults from the community who underwent diagnostic interviews and had a BPD diagnosis. All participants self-reported ER difficulties. Results revealed that race moderated the link between some aspects of ER difficulties and BPD. For instance, relations between (a) nonacceptance of emotions and BPD affect instability, (b) limited access to ER strategies and BPD identity disturbance, and (c) low emotional awareness and BPD diagnosis were stronger among White (vs. Black or East Asian) participants. Implications of these findings for the diagnosis and treatment of BPD across racial groups are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).