Neurilemmoma is a benign encapsulated tumor arising from the sheath of Schwann, occuring along the course ofthe peripheral, cranial, and sympathetic nerves. It was first described histologically by Verocay in 1908 andcalled neurinoma. In 1935 Stout reviewed his 52 cases and coined the term "neurilemmoma," emphasizing the originof the tumor from the nerve sheath. Neurilemmoma in other tissues are not rare, but they have been reported onlyinfrequently in bone. Neurilemmoma involves the bone as three ways : central, peripheral and extraosseous. Theauthors are presenting one case arigin in the periosteum of femur at S.N.U.H. recently. The patient was 22 yearsold female and admitted with complaint of slowly growing mass at thigh during 10 months. Radiologic findingreveals well circumscribed cortical destruction by the expanding extraosseous mass. But there is no evidence ofendosteal proliferation and destruction of medullary cavity. En bloc excision was done and its gross finding waswell encapsulated mass measuring 9.5×7.5×5cm. microscopic findigns reveal typical palisading appearance under theformation of Verocay body (Antoni Type A) in the mixture of more looser and haphazard fashion of cell arrangement(Antoni type B).