Borderline personality disorder (BPD) is a persistent psychological disorder characterized by pervasive emotional difficulties, unstable relationships, identity disturbance and high rates of engagement in self-damaging risk behavior. Prominent theoretical perspectives on BPD suggest that the primary motivational basis for risk behavior is the regulation of negative emotional states. The goal of this study was to test several of the hypotheses suggested by emotion regulation models of risk behavior, using a rigorous experimental design. Specifically, we sought to demonstrate the causal effect of distress on risk behavior among individuals with and without BPD, and to examine motivational and self-regulatory mediators of: a) the relationship between emotion and engagement in risk behavior; and b) the relationship between BPD and distress-induced change in risk behavior. To this end, participants with and without BPD provided ratings of emotion, motivation for emotion regulation and risk behavior in the context of induced calm and distress, and completed a self-report measure of trait self-efficacy for emotion regulation. Results provide partial support for the study hypotheses. Only women with BPD showed an increase in risk behavior in the distress condition, and distress-induced change in risk behavior was predicted by both the intensity of emotion regulation goals and self-efficacy for emotion regulation. Findings support the perspective that risk behavior is enacted strategically in response to negative emotions and associated motivational states. For those with BPD, distress-induced risk behavior may reflect a type of emotion-regulatory resourcefulness that becomes maladaptive when used inflexibly or to the exclusion of other strategies.