Myocardial Infarction with ST segment elevation (STEMI) is a serious disease with a great incidence and a high mortality, caused by severe complications. Acute Myocardial Infarction (AMI) complications are divided in: mechanical, hemodynamic and electric disorders, which negatively influence the prognosis of the disease evolution. Early diagnosis of STEMI with PCI management improve the outcome of these patients with a lower mortality, a higher life expectancy and a better quality of life. In our study we have established that STEMI is more frequent in men (71.3%). These patients had had conduction complications (52.7%), with a prevalence of atrial fibrillation (22.8%) and sinusal tachycardia (8.4%); mechanic complications were observed in 13.9% with the predominance of the free wall rupture (10.8%); hemodynamic complications represented by Killip III (43.6%) and Killip II (38.3%) class. The mortality of the patients caused by STEMI was in 11.4% cases caused predominantly by mechanical complications in 73.8 % cases