27 of 101 patients with complex ventricular ectopy (ventricular bigeminy, couplets, ventricular salvo and ventricular tachycardia) during 24-hour Holter monitoring died during a mean follow-up of 12 months. Mortality was 28% when ventricular salvos had been detected, and 43% in patients with ventricular tachycardia. Detection of ventricular bigeminy had no, registration of ventricular couplets little prognostic significance. Prognosis was altered by presence of cerebral symptoms (dizziness and/or syncope) only for patients with ventricular tachycardia: additional bradyarrhythmia (asystole longer than 1.5 sec due to sinus-atrial or atrioventricular block) did not effect the prognosis, which was significantly worse for patients with a history of myocardial infarction, although patients in the first year after acute myocardial infarction were not included in this study. Prognosis of complex ventricular ectopy significantly worsens with age, it seems of little prognostic significance for patients under the age of 60.