This program appears to be designed to aid the physician in establishing a diagnosis of Chagas disease (also known as American trypanosomiasis). Several patients are presented to illustrate various clinical features of the disease in both its acute and chronic phases. The clinical information discussed is based on a study of 1,500 cases over a period of ten years. The signs and symptoms associated with the acute phase are presented first. These include malaise, fever, edema of the eyelid and face, and an enlarged liver, spleen, and lymph nodes. The chest roentgenographic and the electrocardiographic findings are discussed for acute and chronic phases. The possibility of developing megacolon and megasesophagus in the chronic phase is described. After the clinical features of both the acute and chronic phase are presented, the viewer is asked to establish a diagnosis. The geographic distribution of the disease in South and Central America, and the epidemiological features, diagnostic tests, and causative agent of the disease are described.