The suicidal behavior in adolescence is a problem presenting impressive increase in recent years. Girls tend to commit suicide more often than boys, the attempts of the later, however, are more serious and have more possibilities to lead up to death. A large percentage of youths have a suicidal behavior, due to the various psychological characteristics they present. adolescence is a period in a person’s life that desires, impulses and fantasies are considerably and abruptly increased; while in other phases of the psycho-sexual development they may pass unnoticed or can be confined in the unconscious, during the years of adolescence they emerge in the conscience and clash with reality. The youth uses various defense mechanisms in order to control the intensity of his impulses, but when his efforts are not successful, then he presents psychopathological symptoms. A youth must be considered as a candidate of suicidal attempt: a. if he already has a relevant history, b. if somebody close to him has made such an attempt, c. if he himself has suicidal thoughts, d. if he is depressed. Depression in adolescence is a very grave psychological problem and the major factor responsible for a suicidal behavior, which, unfortunately, cannot be easily diagnosed, because in adolescence the classical adult symptoms remain latent. Since a large increase of psychological problems in youths is expected in the future, we must give priority and focus on the prevention of mental illness. Prevention can be achieved through the proper information of parents and the appropriate education of young couples and parents to be on the various relevant and interrelated psychological, medical and social issues. We hope that the appropriate institutes for the prevention of mental illness will be soon created in our country.