A 32-year-old female patient presented with shortness of breath. The patient had received aortic valve replacement with a 25-mm bioprosthetic valve at the age of 22, and had had two babies, postoperatively. Ten years later, echocardiography showed the calcifi ed bioprosthetic valve with a high peak pressure gradient (70 mmHg) and a reduced valve orifice area (0.46 cm(2)). Electrocardiographically gated multidetector row computed tomography (ECG-gated MDCT) clearly demonstrated calcifi ed bioprosthetic cusps with reduced mobility, and the valve orifi ce area was measured to be 0.64 cm(2) by direct planimetry. These fi ndings observed by ECG-gated MDCT were confi rmed at reoperation. This is the fi rst reported reoperation case of aortic structural valve deterioration clearly visualized by ECG-gated MDCT.