The aim of the study was to investigate the knowledge of Turkish high school counsellors and counselling students about adolescence suicide. The sample consisted of 71 school counsellors and 82 third and fourth year psychology counselling students who completed the Adolescent Suicide Behavior Questionnaire. The results showed that although counselling students have more knowledge than school counsellors, both groups are not well informed about adolescent suicide, with many school counsellors and counselling students unable to determine the risk, precipitating and demographic factors and differential warning signs of adolescent suicide in Turkey.