During adolescence (by convention, 10-19 years of age), the global mortality rates are relatively low in most countries. Nevertheless, suicidal mortality rates are usually second (after all accidents) or third (after accidents and homicides), depending on the country. Rates in males are regularly higher than those in females. Owing to the universal absence of a systematic recording of parasuicide cases, morbidity data are obviously much more difficult to get and to analyze properly. Data based on hospital admissions give only approximations. Nevertheless, in this age group, parasuicide is expected to be many times more frequent in females than in males. Epidemiologic studies on relapses as well as parasuicide follow-up are rare. Taking into account the number and heterogeneity of known risk factors, suicidal behavior prediction is based on probability statistics: valuable only for groups ("high-risk profiles"), never for individuals. This is particularly true in adolescence, when so many changes occur rapidly. Preventative measures are to be discussed according to their pertinence in each of the three classic levels of prevention.