Rectourethral fistula (RUF) is an uncommon pathologic entity of congenital or acquired origin. Acquired lesions may be iatrogenic, traumatic, neoplastic, or inflammatory. The clinical diagnosis of RUF is frequently suggested by fecaluria, pneumaturia, or rectal leakage of urine during micturition. Its imaging diagnosis is based on the demonstration of the contrast-filled fistula track on fluoroscopy/CT or fluid-enhancing sequences on MR. The authors present a case of RUF suspected by PET/CT and confirmed by MR.