Although the sparganosis involving soft tissues, i.e, tongue, cheek, etc., has been frequently reported, the mandibular involvement of sparganosis is not reported up to date. We present a case of intraosseous sparganosis involving whole mandible, which was clinically diagnosed as chronic osteomyelitis. After surgical operation of saucerization for the treatment of chronic osteomyelitis the removed specimens were pathologically examined and finally turned out intraosseous sparganosis. Radiological findings showed irregular multiple radiolucencies in round to ovoid shape throughout both mandibular body areas, of which peripheral rarefying radiopacity was less remarkable compared to the ordinary osteomyelitis. However, the radiolucencies of periapical granuloma, #34-36, were closely associated with the osteolytic lesions of mandibular body. Pathological examination showed a tunnel like space for the passage of sparganum larva, and heavy infiltration of eosinophilicleukocytes. And more, the parasitic tegument materials were found admixed with eggs in the granulomatous lesion, which were gradually degraded and resolved. Taken together, we presumed that the mandibular inflammatory lesion was primarily involved with sparganosis and secondarily aggravated by the periapical infection of #34-36.