This laboratory study examined the emotional reactivity of persons with heightened borderline personality (BP) features to a social rejection stressor. Participants with high levels of BP features (n = 43) and controls with low levels of BP features (n = 67) were randomly assigned to a condition involving negative evaluation and social rejection based on personal characteristics, or to a condition involving a frustrating arithmetic task and negative evaluation based on performance. Hypotheses were that the high-BP individuals would demonstrate greater increases in negative emotions, shame, and anger in response to the social rejection/negative evaluation stressor, compared with the frustrating arithmetic task. The high-BP group showed significant increases in negative emotions in both conditions, significant increases in shame only in the frustrating arithmetic task, and significant increases in hostility only in the social rejection condition. In contrast, low-BP controls showed significant increases in negative emotions generally in the frustrating arithmetic condition and shame specifically in the social rejection condition. These findings highlight the emotion and context-specific nature of emotional reactivity in relation to BP features.