Introduction. Infective endocarditis is defined as an infection of the endothelial surface of the heart and heart valves, above all. It is a great challenge for doctors to diagnose infective endocarditis especially in primary health care, because this is a disease in evolution, bearing in mind changes in epidemiological and clinical characteristics, which developed in the last decades. Even today this is a very severe and insidious disease, with poor prognosis and high mortality. Prevention of Infective Endocarditis. Although previous guidelines proposed a limitation to prophylaxis in patients at increased risk of adverse outcome of infective endocarditis, new guidelines recommend the principles of antibiotic prophylaxis when performing procedures at risk of infective endocarditis in patients with predisposing cardiac conditions, and limit its indication to patients at the highest risk of infective endocarditis undergoing the highest risk procedures. Conclusion. Despite the fact that previous guidelines for diagnostics and treatment of infective endocarditis were published only several years ago, the Task Force on Prevention, Diagnosis and Treatment of Infective Endocarditis of the European Society of Cardiology identify infective endocarditis as a clearly evolving disease, with changes in its microbiological profile and higher incidence of health care associated cases which has brought about a need for new recommendations to help health care providers in making clinical decisions including preventive measures and antibiotic prophylaxis. As a novelty, a group of patients at the highest risk of infective endocarditis was defined as well as the type of procedures at risk divided into four categories.