A case of human proliferative sparganosis, the first in the southern hemisphere, is reported. The patient had multiple nodular, papular, acne-like lesions, gynecomastia, and large subcutaneous abscesses. Laboratory findings showed that he also had severe anemia of the type associated with infection and chronic diseases, leukocytosis, eosinophilia, and severe hypoalbuminemia and hypergammaglobulinemia. His cellular and humoral immune responses were unaltered. New aspects on the functional repercussion of the parasitism of the human host by Sparganum proliferum are discussed. Treatment with mebendazole was ineffective; the patient's tolerance for the newer drug praziquantel was extremely poor.