Suicide is a major public health problem among adolescents. Although the event is rare, and rates have stabilized and even shown slight reduction in recent years, suicide has nevertheless become the second leading cause of morbidity among youths aged 15 to 24, which is otherwise a robust and relatively disease-free population. Although research on predictive factors has yielded increasingly sensitive indices of who the high-risk adolescent might be, the inherent difficulty of predicting rare events from common ones has made sensitive and specific prediction most elusive. Current neurobiologic research holds promise for the use of biologic markers in the identification of high-risk adolescents, and pharmacologic research may yield further advances in the treatment of affectively disordered youths. At this point, the most promising approaches to treating adolescent suicide appear to be (1) treatment of disorders antecedent to suicide crises, such as depression, substance abuse, family conflict, and conduct disturbance, and (2) prevention efforts targeting known high-risk groups, such as affectively disordered young men with accompanying alcohol and drug involvement and other antisocial behavior.