Tetralogy of Fallot (TOF) is a congenital heart disease that is usually diagnosed and treated during infancy. Only 3% of such patients reach the age of 40 without surgery. We describe a 61-year-old woman with uncorrected TOF that was successfully treated by radical surgery. The patient presented with exertional dyspnea, insomnia, and malaise. Echocardiography and cardiac catheterization indicated a dilated, severely hypertrophic right ventricle, ventricular septal defect, an overriding aorta, and infundibular stenosis in the right ventricular outflow tract. All symptoms disappeared after full surgical correction, which remains the preferred treatment for adult TOF because it confers long-term survival and an improved quality of life.