The research shows that more than 50 % of deaths related to cardiovascular diseases are connected to sudden cardiac arrest. The incidence of sudden cardiac arrest is more often in men than in women. For prevention of the sudden cardiac arrest, it is important to conduct regular educations of medical staff, patients, and the public. The focus of this paper were the cases of the sudden cardiac arrest in children and professional athletes. With the progress of diagnostics and treatment in the paediatric science the incidence of the sudden cardiac arrest in children is reduced. With the professional athletes it is necessary to conduct regular organized medical exams for the professional and recreational athletes. In prevention and treatment of the sudden cardiac arrest implementation of cardioverter defibrillator is cheaper and more efficient than the application of drug therapy. Nurse has an important role in the first contact with the patients and establishing an accurate diagnosis and education of patients.