The present case is a report of a patient with malignant schwannoma of the posterior tibial nerve in the popliteal fossa. A review of the literatures revealed no case in this location. A malignant schwannoma is a relatively rare tumor arised from schwann cells of the peripheral nerve sheath. Malignant schwannoma recurs as a rule and metastasizes at a late stage to lung and centripedally to proximal nerve but rarely to regional lymph node. We have experienced one case of malignant schwannoma of the posterior tibial nerve associated with von Recklinghausen's disease. The treatment of choice is one stage radical surgery. And excisional biopsy for diagnostic or therapeutic purpose is condemmed The prognosis is usually poor.