Aim: to evaluate the clinical and pathogenetic role of free fatty acids in myocardial infarction-segment elevation ST. Material and methods. The study enrolled 133 patients (aged 60,25±1,12 years) diagnosed with ST elevation myocardial infarction. Within 30 days after myocardial infarction fixed development of acute heart failure, rhythm disturbance, early post-infarction angina. Depending on the availability of these complications, patients were divided into groups and then comparing the clinical history and laboratory survey data, which included a definition of traditional parameters of lipid and free fatty acids. Results. Lipid metabolism is not dependent on the availability of hospital complications were characterized by increasing concentration of atherogenic and anti-atherogenic fractions of cholesterol reduction. The content of free fatty acids in the 1st day in all groups of patients was higher compared to the control, a 12-th day of their reduced level, but was higher than the control. Wherein MI complications associated with higher fatty acids on the 1st and 12th day. Conclusion. Among lipid profile, free fatty acids, are the most important prognostic: high concentrations of fatty acids in the hospital period increases the risk of early complications of MI.