SummaryMitral and pulmonary staphylococcal endocar-ditis in a heroin addict.Endocarditis and other infectious diseases are a most frequent complication of heroin addiction, second only to overdosage. A lethal case of staphylococcus aureus endocarditis in a heroin addict patient is reported. Findings included involvement of mitral and pulmonary valves, pericarditis, peripheral and pulmonary septic emboli, and renal failure. Pathological examination de-monstrated disseminated phagocytised talc particles.Perusal of previously reported cases pointed out several characteristics of heroin addict endocarditis. Tricuspidian staphylococcal endocarditis is the rule whereas pulmonary valve involvement is exceptional. High bacterial activity is assumed to be the cause of the severe and rapid evolution which is commonly observed. Heart murmurs are generally of poor diagnostic value. Most frequency associated complications include pulmonary emboli with secondary abscess, parenteral injection of talc or cotton particles, and serum hepatitis (HAA).Increased concentration of immunoglobulins (IgM) is frequently demonstrated.Renal complications in heroin addict patients (glomerulonephritis) are associated with antigen-antibody deposits (unknown antigen) upon the glomerular basement membrane, as described in bacterial endocarditis and particularly in staphylococcal endocarditis.