Infective endocarditis (IE) is an endocardial lesion caused by bacterial and/or fungal infection that most commonly affects the heart valves and/or the endocardium around implanted intracardiac devices. In general, IE is classified as a rare disease, but there has been a steady increase in incidence, primarily in high-income countries. The danger of IE lies in the high frequency of complicated course of the disease and the risk of lethal outcomes both at the inpatient stage of treatment 25.0% and in the distant period 30-40%. The annual incidence is from 3 to 10 per 100,000 people. In addition to the difficulties in the diagnosis of IE, the most challenging aspect is the prescription of effective antibiotic therapy, especially in the context of unidentified etiology of IE and the growth of multi-resistant pathogens. Many solutions are used to achieve successful therapy of IE, including the prescription of combined antibiotic therapy, the use of new modern antibacterial drugs, the prescription of therapy taking into account the sensitivity of the pathogen, but the failure of treatment and the number of resistant pathogens are only increasing. Moreover, antibacterial therapy is relevant both in patients on conservative treatment of IE and after cardiac surgery, among whom the risk of nosocomial or healthcare-associated infections is additionally increased. Thus, new ways of modernising IE therapy are needed. Phage therapy is considered one of the promising strategies \[6-8\]. Bacteriophages are certain viruses that naturally infect bacteria and are used as antibacterial treatments. Phagotherapy is used as antibacterial drugs that can induce lysis of target pathogens.