Electrical storm (ES) defined as the occurrence of three or more distinct episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) in 24 hours, requiring the intervention of the ICD, are not rare events. Identification of the risk predictors of ES occurrence appear to be important, since these events are associated with increased morbidity and mortality. The aim of the study was to assess the prevalence, features, and predictors of ES in patients with ICD and in patients in whom ICD was implanted for primary prophylaxis vs. secondary prophylaxis. A retrospective analysis of 250 patients with ICD and mean age 62.76 +/- 11.20 years, with amean follow-up of 52.4 +/- 33.2 months was made based on initial files at implantation and on subsequently results from the devices interrogation. The ICD was implanted for primary prevention of sudden cardiac death in 198 patients (79,2%) and for secondary prevention in 52 patients (20.8%). ES was present in 22 (8.8%) of patients, 17 (8.5%) patients with primary prophylaxis and in 5 (9.6%) patients with secondary prophylaxis. We found no clinical predictors of ES. In our study, the patients presenting ES had a slightly higher LVEF as compared with patients without ES: (35.5 +/- 10.47% vs. 29.9 +/- 11.63%, p = 0.03 for the whole study population and 34.7% vs. 28.31%, p = 0.011 for primary prophylaxis group). Lack of administration of spironolactone seems to be associated with a higher incidence of ES (18% vs. 5.9%, p = 0.003 for the whole study group and 20% vs. 6%, p = 0.004 for primary prophylaxis group).