Lipoma is a benign soft tissue tumor of fat and consider as the most mesenchymal neoplasm which highly occurrence on the trunk and extremities. It’s prevalence in oral and oropharyngeal region is relatively uncommon. Few oral cavity lesions occur before the third decades of life with a fairly balanced sex distribution. Lipoma histopathologically sub classified to fibrolipoma, angiolipoma, myxolipoma myolipoma and osteolipoma according to presence of fibrotic connective tissue, highly vascular, myxoid changes, smooth muscle bundles and area of bone or cartilage metaplasia just close to mature fat cells.,Osteolipoma is a rare variant of lipoma that had mature fat cells as main tissue with area of bony changes. In head and neck region osteolipoma has been reported in CNS, neck, scalp and lat pharyngeal space., In review of English language articles there was eight reported case of osteolipoma in oral cavity.,Our case is an osteolipoma of the floor of mouth in 54 years old age woman with submental mass from 6 months ago and radiographic report suggests teratoma with some radiopaque nests.

Key words: Oral cavity, Tumor, Osteolipoma