Transcatheter aortic valve implantation (TAVI) is widely accepted as the treatment for patient with severe aortic stenosis (AS) whose prognosis may be over one year; however, there is no consensus concerning extremely high-risk patients whose prognosis may not exceed one year. We herein report a highly frail patient with severe AS complicated with transthyretin-type cardiac amyloidosis who had a very poor prognosis. Given his condition, we treated him by percutaneous antegrade balloon aortic valvuloplasty (A-BAV) instead of TAVI. A-BAV may be a beneficial option for treating extremely high-risk severe AS patients, including those with cardiac amyloidosis.