Benign solitary osteochondroma is uncommon in the vertebra (2%). Vertebral ostoechondroma arises predominantly in the lumbar and cervical regions, and rarely in the sacrum. We describe a case of a sacral solitary senescent osteochondroma compressing the sciatic nerve, producing sciatica. The tumor was removed by posterior paramedian incision. The excised mass was cylindrical, measuring 3.5x1x1 cm in size and consisting of lamellar bone with Haversian system similar to the architecture of normal cortical bone and trabecular bone.