Suicide during adolescence represents the second major cause of death in Western European countries. In Switzerland, death rates for suicide approximate 4 in 100,000 among girls and 20 in 100,000 among 15- to 19-year-old boys. These rates are four times higher for young adults from 20 to 24. Swiss adolescents exhibit the highest death rate by suicide among developed countries, and these rates have increased during the last 15 years at a faster pace than in the general population. Suicide attempts, above all by ingestion of drugs, represent a very common cause of hospitalization, especially among girls. The annual rate of suicide attempts approximates per thousand. The causes for suicidal conduct as well as its circumstances are various. The best prevention remains an individual approach. Health professionals as well as professionals from other background (teachers, social workers) have thus to find appropriate answers: When they meet adolescents who seem to suffer from psychosocial burdens, they should always look for suicidal thoughts or projects and then, if necessary, offer a therapeutic frame (on an individual basis or within the family). Prevention within the general public should mainly address nonspecific topics, such as the mental health of adolescents, their coping abilities and their environment; prevention programs specifically addressing the problem of suicide among adolescents have not proven beneficial and may even be harmful. On an individual as well as a collective level, each professional should be alert to his own psychological attitudes and reactions, which may be counter-productive if he is overwhelmed by the fears and stress that the act or threat of suicide generates.(ABSTRACT TRUNCATED AT 250 WORDS)