Chagas' disease is one of the most important public health problems in South America and Mexico. Migrations from rural areas into urban zones have contributed to the spread of the disease. The main targets of the disease within the body are the heart, the alimentary tract, and the nervous system. In the acute phase of the disease, the parasite responsible for the disease can be identified in the blood by direct examination. This article identifies the parasite responsible for transmission of the disease and discusses symptoms, means of identification in the patient, and treatment.