The pathological systematized study of the brain of 31 cases of the chronic cardiac form of Chagas' disease was undertaken. Elective parenchymatous necrosis was found in 64.5% of cases, mainly in cerebellar Purkinje cells, and in thalamic nuclei. Also found were multiple foci of old micronecrosis (51.6%) mostly in the cerebral cortex, old cerebral infarcts (22.6%), cortical laminar necrosis (16.1%) and cerebral cortical atrophy (3.2%). These findings are not specific and can be explained by thromboembolic phenomena and hypoxemia following from congestive heart failure and disturbances of the cardiac rhythm.