Positive and negative affect, emotion regulation and self-efficacy are important mechanisms in borderline personality disorder (BPD), but their contribution is still not clear. Our goal was to explore their role in relation to typical BPD outcomes: psychiatric hospitalizations, suicidal behaviors and depression. The sample comprised 88 women with BPD. The unique contribution of positive and negative affect, the regulation of emotions and self-efficacy in outcomes were analyzed. Positive (β= -.40, p< .001) and negative (β= .54, p< .001) affect contributed uniquely to depression. Emotion suppression was the only predictor of the number of hospitalizations (β= -.29, p<.05). Self-efficacy was uniquely related to suicide attempts (β= -.26, p< .05) when controlling the rest of the variables. Positive and negative affect, emotion regulation and self-efficacy are important psychological mechanisms uniquely associated with specific emotional and behavioral outcomes in BPD. These findings will help to design interventions in a more effective way and tailor treatments for individuals with this disorder.