This report describes the clinical spectrum and outcome of the hemophagocytic syndrome (HS) in 5 HIV infected patients. All 5 patients presented with fever, hepatomegaly and/or splenomegaly, confusion or coma and respiratory symptoms. Severe anemia was associated with thrombocytopenia and with neutropenia in 4 cases. Diffuse intravascular coagulopathy was present in 2 cases. Liver function tests were abnormal in three patients. The diagnosis of HS was made 2 to 12 weeks after the onset of symptoms and required in most patients repeated examinations of the bone-marrow, showing infiltration by histiocytes with prominent phagocytosis of blood cells. In one case this infiltration was not seen in the bone-marrow but only in the liver and the spleen. Varicella, mycobacterium infection, oesophageal candidiasis, Kaposi sarcoma were observed in the evolution of 3 patients. Anaplastic large cell Ki-1 lymphoma was present in one case. Four patients died as a result of complications of HS. The one patient with lymphoma survived.