Despite the appearance in clinical practice of modern treatment modes as thrombolysis and percutaneous coronary intervention, in-hospital mortality from acute myocardial infarction remains an important problem. In this paper we review recently published data concerning risk stratification in the acute phase of myocardial infarction, different factors affecting the prognosis, their dynamics in the course of the disease, and inter-factor relations. We emphasize the prognostic value of three factors: heart rate variability, left ventricular dysfunction and arrhythmias. Changes in heart rate variability are discussed in association to location of myocardial infarction, patency of infarct-related artery, the chosen treatment mode and its timing. Left ventricular diastolic function and right ventricular function are shown to be predictors of morbidity and mortality after myocardial infarction besides left ventricular systolic function. We also present the latest data concerning the prognostic implication of arrhythmias, their relation to left ventricular function and autonomic nervous system balance. Atrial fibrillation and atrial flutter appear to be important factors in predicting mortality after myocardial infarction, especially in the elderly, as well as ventricular arrhythmias - sustained ventricular tachycardia and ventricular fibrillation.