Disturbances of endothelin production or clearance contribute to the pathophysiology of several cardiovascular diseases including Chagas disease cardiomyopathy caused by the protozoan Trypanosoma cruzi. In rats, endothelins contribute to control the acute phase, probably by stimulating nitric oxide production. We point out the necessity for new studies to better evaluate high levels of endothelin in the course of other infectious diseases, for which only its detrimental effects have been emphasized.