We describe two cases of disseminated histoplasmosis, which are of interest due to their severity and the infrequency of this infection in our environment. Both children were immunocompromised immigrants from Latin America who developed prolonged fever, weight loss, hepatosplenomegaly and pancytopenia. One patient had respiratory symptoms with associated alterations on x-ray, while no radiological alterations were found in the other patient. Despite administration of broad-spectrum antibiotics and extraction of samples for microbiological analysis, both patients had a rapid and fatal outcome and the diagnosis was made post mortem. Because of its severity, disseminated histoplasmosis should be considered in the differential diagnosis of fever, hepatosplenomegaly and pancytopenia, with or without alterations on chest x-ray, in immunosuppressed children who were born in or have visited endemic regions. In these patients, therapy should be started immediately without waiting for the results of diagnostic tests.