We report a case of a 55-year-old woman, who presented with a vague pelvic pain and was found to have an ectopic pelvic kidney involved by a mass. Preoperative assessment was done by multi-slice CT and 3D-CT angiography. According to our knowledge only eight cases of pelvic kidney tumor have been reported in the literature and our case is the first report of using multi-slice CT and 3D-CT angiography in the preoperative evaluation of these cases.