The pathological findings in the brain of patients who died with idiopathic cardiomegaly are reported. The major findings in the 38 studied cases were cerebral infarcts (10,5%) and cerebral atrophy (7,9%) besides the nonspecific histological changes represented by neuronal ischemic alteration, satellitosis of nerve cells and swollen and hyperplasia of endothelial cells in capilaries of the cerebral cortex. These findings were considered a consequence of the venous stasis of the congestive heart failure. These data were compared to those seen in the brain of patients with heart failure in the course of chronic Chagas disease. The morphological findings were similar. The frequence of infarcts and atrophy was higher in the cases of Chagas disease and the cerebral atrophy was seen in an younger group of patients compared to the cases of idiopathic cardiomegaly. It seems that there is another factor also responsible for the occurrence of cerebral atrophy in Chagas disease, since from the clinical and hemodynamic point of view both cardiopathies have many similarities.