Syncope and presyncopal states are a common pathology in children and adolescents. They may be mild physiological disorders or life-threatening events. Their diverse aetiology makes the diagnostics difficult and expensive. The aim of the study was to analyse the causes and the effectiveness of diagnostic evaluation of syncope in children and adolescents. Neurovegetative disorders were the most common cause of syncope in children. Of essential practical importance was the orthostatic test, allowing diagnosis in 73% of cases. The causes were not established in 12% of patients.