The authors report a case of a 51 year-old woman with spontaneous Grynfeltt’s hernia. Computerized tomography accurately displayed the anatomy of the lumbar region, thus aiding diagnosis and treatment. A double layer polypropylene mesh was used for the repair, placed in the pre peritoneum and sutured to the margins of the hernial defect avoiding muscles and fascias. The use of a double layer prosthesis and reduction of tension on the suture line allow a sound repair, with minimal postoperative pain and immediate resumption of daily activities.