A 76-year-old man had been under observation for nephrotic syndrome. He suffered from hypotension and transient loss of consciousness. He was diagnosed with thoracic aortic aneurysm and severe aortic valve stenosis. Ascending aorta replacement concomitant with aortic valve replacement was performed uneventfully. He was diagnosed with light chain amyloidosis by pathological examination of the resected ascending aorta. He was received referral treatment for amyloidosis.