Prevention of youth suicide is described. A model of those at risk is given; this model suggests that most adolescent suicides are drawn from a definable pool of at-risk individuals. Prevention techniques are discussed. Primary prevention reduces the number of at-risk individuals (e.g. treating mental disorder) and limits their access to lethal methods. Secondary prevention provides help for those already suicidal (e.g. crisis hotlines, school-based prevention programs). (44 refs.)