Osteoid osteoma is a benign tumor of the bone which has seldom been described in the jaws. It was first described as a distinct clinical entity by Jaffe in 1935. Lichtenstein defined osteoid osteoma as a "small, oval or roundish tumor like nidus which is composed of osteoid and trabeculae of newly formed bone deposited within a substratum of highly vascularized osteogenic connective tissue". The most interesting clinical feature of osteoid osteoma is the exquisite pain produced by a very small lesion, never greater than one centimeter in diameter. It accounts for 3% of all primary bone tumors, and about 10% of benign bone tumors. About 80% of cases of osteoid osteoma occur in long bones, while less than 1 % occur in jaws. We report a case of an 18-year-old male patient with osteoid osteoma of right side of the mandible.