We report an autopsy case of right isomerism in a 42-year-old Japanese man. Although he had not undergone any surgical intervention, he was healthy and did not exhibit any symptoms of heart failure. The cardiac findings indicated right isomerism with complex and severe cardiac malformations, including a morphologically common atrium, common atrioventricular valve, double inlet right ventricle, total anomalous pulmonary venous drainage, pulmonary outflow obstruction, pulmonary atresia, and major aortopulmonary collaterals from the descending aorta. He had no spleen, and exhibited some gastrointestinal malformations. The absence of risk factors for mortality from right isomerism, such as pulmonary venous obstruction, AV valve regurgitation, sepsis or severe arrhythmia, might have contributed to the longevity of this patient. The presence of pulmonary outflow obstruction that is reported to confer a better prognosis might also have contributed to his longevity.