Borderline personality disorder (BPD) and alcohol use disorder frequently co-occur, yet we know relatively little about risk processes underlying this association. Previous research with nonclinical samples has highlighted how drinking motives may link personality characteristics with heavy alcohol use and problems. The present study substantively extends previous research by examining if drinkers with BPD had higher levels of alcohol use problems compared with drinkers without BPD and similar levels of alcohol use involvement. Multiple domains of impulsivity and affective instability were examined as dimensional markers of risk that may increase alcohol problems for individuals with BPD. Furthermore, multiple domains of drinking motives were examined as potential mediators accounting for the association between BPD and alcohol-related problems. Participants were 81 current drinkers (n = 39 with a current diagnosis of BPD). Results indicated that those with BPD endorsed more alcohol problems compared with non-BPD drinkers, F(1, 77) = 22.26, p < .001. These findings remained after accounting for multiple domains of impulsivity and affective instability. The indirect effects of coping and conformity-related drinking motives partially accounted for the relation between BPD and alcohol problems. Research examining differential response to alcohol for individuals with BPD is needed to directly test if acute alcohol consumption is particularly effective at reducing negative affect for adults with BPD. Offering alternative methods of managing uncomfortable or painful states and/or fitting in with others socially may represent particularly important targets for intervention efforts that decrease these reasons for drinking. (PsycInfo Database Record (c) 2020 APA, all rights reserved).