A 73-year-old male presented with a 2 week history of gross haematuria and faecal material in the urine. Bone scan for cancer work-up showed 99T(cm)-MDP radioactivity accumulation in the transverse and descending colon. A 99T(cm)-DTPA diuretic renogram was arranged to study renal function and to determine the location of the enterovesical fistula. Diuretic renography demonstrated extraurinary tract radioactivity in the sigmoid colon in the early images, extending to the descending and transverse colon in the subsequent dynamic images. A sigmoid colon adenocarcinoma with bladder wall invasion and fistula formation was confirmed at surgical operation. The impressive dynamic diuretic renography study in this patient was helpful in determining the location of the fistula and in planning surgical management.