Heart murmurs are usually generated by a turbulent and increased flow of blood. The majority of soft systolic murmurs are innocent (benign). The intensity (loudness) of a murmur does not always correlate with the severity of the valvular disease. The intensity of a murmur induced by significant valvular disease usually decreases in severe heart failure, or the murmur may even disappear altogether. A murmur suggestive of new valvular regurgitation in a febrile patient should always arouse the suspicion of endocarditis. If the condition of a patient with an artificial heart valve suddenly deteriorates, complications relating to the valve prosthesis should always be borne in mind. Endocarditis prophylaxis is no longer considered necessary in patients with acquired valvular disease. This article does not address causes of murmurs that are rare in adults, including pulmonary valve stenosis, mitral valve stenosis, congenital heart diseases, ventricular septal defect and pericardial rub.