Myeloid sarcoma (MS) is a rare extramedullary myeloid tumour. It has been reported in various sites, including lymph node, bone, skin, soft tissue, various organs and the CNS. It may precede or occur concurrently with acute myeloid leukemia. Urinary bladder involvement is extremely uncommon. We report a 70-year-old female who had MS of the urinary bladder, presented with frank and persistent hematuria associated with lower abdominal pain. She subsequently had tumour seeding in the abdominal skin via percutaneous suprapubic catheter. Tumours from both the urinary bladder and skin showed immature cells that were immunoreactive toward LCA (focal), MPO (strong), CD99 (weak) and CD117 (weak). Summary of cases in the literature is presented. The potential of its misdiagnosis and the useful markers for the diagnosis of MS are discussed.