Massive bladder hematoma can occur following a trauma, neoplastic states, or as a longterm side effect of a pelvic irradiation therapy. It is reported, albeit rarely, in the patients with amyloidosis which can affect bladder and can manifest itself as hematoma. However, it hasn’t been yet reported in kidney transplant recipients. A 31 year-old male with chronic glomerulonephritis received kidney transplantation. He developed proteinuria and frequent episodes of lung infection because of bronchiectasis after seven years from transplantation. Duodenal biopsies showed AA-amyloidosis. Macroscopic hematuria appeared, and cystoscopy revealed hematoma and perforation of bladder wall. A 56 year-old male with secondary amyloidosis due to familial Mediterranean fever had kidney transplantation. After two years, cystoscopy was performed because of macroscopic hematuria and revealed large hematoma that completely filled the bladder. To our knowledge,these are the very first cases with AA amyloidosis who developed spontaneous bladder hematoma in kidney transplant recipients.