To report one case of colovesical fistula after the diagnosis of unresponsive urinary tract infection.The 76-year-old patient underwent a diagnostic work up including cystography, cystoscopy and barium enema.Cystography revealed an image of the sigmoid colon, and cystoscopy showed a granuloma at the bladder dome. A fistula was identified underneath. A colovesical fistula was diagnosed and several intestinal germs grew on urine cultures. Partial cystectomy and end to end anastomosis of the sigmoid colon were carried out. Pathology report showed a well-differentiated adenocarcinoma which invaded down to the bladder mucosa.Inflammatory diseases are the main the etiology of colovesical fistula, followed by neoplasias. We reviewed around 170 cases reported in our country. It is important to identify the fistula by means of the gastro-intestinal series and the study of the lower urinary tract when treating patients with urinary tract infection difficult to control. We suggest the best radical therapy is surgery in a single procedure.