Neurilemmoma is a benign encapsulated tumor arising from the sheath of Schwann, occuring along the course of the peripheral, cranial, and sympathetic nerves. It was first described histologically by Verocay in 1908 and called neurinoma. In 1935 Stout reviewed his 52 cases and coined the term“neurilemmoma,”emphasizing the origin of the tumor from the nerve sheath. Neurilemmoma in other tissues are not rare, but they have been reported only infrequently in bone. Neurilemmoma involves the none as three ways: central, peripheral and extraosseous. The authors are presenting one case arising in the periosteum of femur at S.N.U.H. recently. The patient was 22 years old female and admitted with complaint of slowly growing mass at thigh during 10 months. Radiologic finding reveals well circumscribed cortical destruction by the expanding extraosseous mass. But there is no evidence of endosteal proliferation and destruction of medullary cavity. En bloc excision was done and its gross f nding was well encapsulated mass measuring 9.5$ imes$7.5$ imes$5cm. Microscopic findings reveal typical palisading appearance under the formation of Verocay body (Antoni Type A) in the mixture of more looser and haphazard fashion of cell arrangement (Antoni type B).