Introduction . Acute coronary syndrome (ACS) is the main cause of death in elderly patients who suffer worse from percutaneous coronary interventions (PCI), and new cardioprotection techniques are in high demand. Aim . To study the efficacy of levocarnitine in preventing complications due to PCI in elderly patients with acute coronary syndrome. Materials and methods . 80 ACS patients were randomized into 2 groups of 40 people: the main group was the average age of 78 (75, 93), received 1.0 g of levocarnitine intracoronary, followed by an intravenous infusion of 2.0 g/day for 3 days; and the control group of age 77 (75, 91) received placebo administration. PCI was performed an average of 3.5 hours after the onset of ACS symptoms. The MB fraction of creatine phosphokinase (CPK-MV) and highly sensitive troponin I (hsTrI), ECG and EchoCG parameters in dynamics, course and outcomes were determined. Results . The dynamics of biomarker levels was more favorable in the main group, where there was a smaller increase in hsTrI at 1 day after PCI and an accelerated decrease at 3 day after PCI. CPK-MB on day 3 in the main group was significantly lower than the control level (p < 0.001). The significantly lower average left ventricular ejection fraction in the main group initially (p < 0.023) significantly exceeded the control level on day 3 after PCI (p < 0.001). There was a faster positive dynamics of the ECG and a tendency to decrease the frequency of arrhythmic episodes in the main group compared with the control group. There was no hospital mortality in the main group, and it was 10.0% in the control group. Conclusions . The described technique of adjuvant cardioprotection in PCI appears to be an available, effective and safe addition to the standard provision of reperfusion in elderly patients with ACS.