Mucinous adenocarcinoma of the urinary bladder is a rare primary urologic disease, poorly responsive to radiation or chemotherapy as first-line treatment.After trans-urethral resection of the bladder, a 62-year-old woman was diagnosed with mucinous adenocarcinoma of the urinary bladder. An upper gastro-intestinal endoscopy and a colonoscopy excluded any primary site of origin from those gastro-intestinal tracts. After whole-body CT staging scans, an anterior pelvectomy was performed, confirming a mucinous adenocarcinoma of the bladder, with no extra-vesical spreading. Some onco markers were sampled before surgery, and Ca 19-9 showed very high values, with a decreasing trend after pelvectomy. Six month after surgery, bilateral inguinal lymph node dissection was performed because of bilateral palpable masses - histologic examination showed a single metastatic node. The patient also received external radiotherapy of the inguinal area. Twenty-eight months after pelvectomy, the patient appears healthy.Early radical surgery with or without adjuvant radio-chemo-therapy appears to be the best option for mucinous adenocarcinoma of the bladder, and a good outcome is likely to be related with a confined disease and small tumor size. In addition, Ca 19-9 sampling proves to be useful in tumors that produce markers.