Two different histological types of congenital Chagas disease are defined. In one type, parasites were seen within the skeletal and cardiac fibers, and in the other, they are found mostly within the cells of the reticuloendothelial system. The latter was often associated with parasitized giant-cells with a single, lobulated, hyperchromatic nucleus. In 24 placentas, the most consistent findings were villous and intervillous inflammatory infiltrates. Amastigotes of Trypanosoma cruzi were found mostly in the chorionic villi and in the chorionic plate, and less frequently in the fetal membranes.