Suicide rates among adolescents are higher than ever recorded, but there are much controversy on the definition of suicide, research method, and the etiology of this problem. This paper discusses the etiology of suicidal adolescents from three major perspectives -indi-vidual factors, family factors, and social factors - since no single factor sufficiently explains this. In addition, it suggests treatment and prevention of adolescent suicide as a guideline for mental health practitioners, school personnel, and others who are in contact with adolescents.