Three cases of haemophagocytic syndrome (HPS) due to histoplasmosis in patients with the acquired immunodeficiency syndrome (AIDS) are described. At admission all had pancytopenia and the bone marrow aspirate showed typical haemophagocytosis and the presence of intracellular inclusions compatible with Histoplasma capsulatum. One patient had also cerebral toxoplasmosis. One patient died shortly after admission from multiple organ failure. Two patients survived, one treated with fluconazole and another with amphotericin-B with good response and progressive increase in their blood cell counts. We suggest that haemophagocytic syndrome due to disseminated histoplasmosis should be included in the causes of pancytopenia in patients with AIDS. Bone marrow aspirate is the best method for diagnosis.