OBJECTIVE The scant references in the literature on the use of the appendix in ureteral substitution prompted us to describe the present case in whom this technique was utilized. METHODS The surgical technique of appendiceal interposition to repair a defect approximately 10 cm long in the right ureter is described. Following excision of a mass arising from the adnexa that entrapped the ureter at the level of the pelvis, the defect was repaired with the appendix. RESULTS At two years follow-up, the patient is well and right excretory system function is normal. CONCLUSIONS Ureteral repair with the appendix is simple and easy to perform. However, the indications for appendiceal interposition are more limited than those of the classical surgical techniques.