Among 26 heart transplant patients, four had Chagas' disease cardiomyopathy. They were male patients, aged 28 to 43 years; three were in New York Heart Association class IV, and one was in class II but with refractory arrhythmias. The immunosuppressive protocol was cyclosporine and steroids in the first patient, and cyclosporine, azathioprine, and steroids in the last patient. Three patients had one or more rejection episodes, and one had none. One patient had a lymphoproliferative intestinal disease. Three patients had a new acute phase of Chagas' disease in postoperative days 59, 81, and 420, with fever, skin lesions, and myocarditis. The Trypanosoma cruzi was found in skin lesions in all three patients and in the myocardial biopsy in two patients. The laboratory tests did not show the expected results for the acute phase. All the alterations were reversed by specific therapy in a few days. One patient died on postoperative day 197 from rejection, and the immunosuppression was diminished because of the lymphoproliferative disease; the others were well 107, 160, and 500 days after the transplantation. The conclusions were as follows: (1) It seems that steroid pulse therapy predisposes the patient to a new acute phase of Chagas' disease. (2) Clinical presentation and laboratory test results of the acute phase are not the usual. (3) Specific drug therapy reverses all the alterations of this acute phase in a few days. (4) Although additional care is necessary and specific complications are expected, heart transplantation can be done with good results in patients with Chagas' cardiomyopathy.