This study examined the association of novelty seeking, harm avoidance, and reward dependence with different types (suicide attempts vs. nonsuicidal self-injury) and aspects (medical risk, impulsiveness, suicide intent) of self-injury over a 12-month period. Fifty-five female patients with borderline personality disorder enrolled in clinical trials completed Cloninger's Temperament and Character Inventory at pretreatment as well as the Suicide Attempt Self-Injury Interview at four-month intervals starting from the pretreatment assessment. Regression analyses indicated that the reward dependence subscale of attachment, a protective factor, was most consistently and uniquely associated with aspects of self-injury, including prestudy and prospective nonsuicidal self-injury and suicide intent, and prospective suicide attempts. After controlling for prestudy self-injury, few temperament variables predicted prospective self-injury. Higher scores on both the novelty seeking subscale of impulsiveness and the reward dependence attachment subscale were associated with lower prospective suicide intent even after controlling for pre-study suicide intent.