Chagas' disease is a major problem in Central and South America10. The disease is caused by Trypanosoma cruzi, a protozoon which may inhabit the blood and tissues of both man and animals. Although it may produce marked enlargement of several hollow viscera, myocardial involvement is the hallmark of chronic Chagas' disease. The clinical picture of chronic Chagas myocardites is one of insidious, progressive, prolonged congestive heart failure and cardiac enlargement. The almost invariable arrhythmias make syncope and sudden death common in patients both with or without congestive heart failure. Electrocardiographic abnormalities occur in 87 percent of patients with chronic Chagas" disease and are often the initial manifestation of illnes. Pathological findings include mural trombosis which often results in pulmonary and central nervous system embolization. Trypanosoma cruzi is in general transmitted to human beings by the bite of haematophagus insects of the reduviidae family, but in the last years reports pointing out the importance of blood transfusions as infectious sources of Trypanosoma cruzi are becoming more and more frequent. The authors present a case of a male young architect whitch contrated Chagas' disease probably by a blood transfusion and latter developed "locked-in" syndrome. It is discussed the importance of blood transfusion as a source of transmission of the disease even in non-endemic áreas and the need to controlling all blood transfusions in countries where Chagas' disease is endemic. The authors also point out the importance of computed tomography in the diagnosis of lesions in the pons.