Giant cell tumor of soft tissue (GCT-ST) is a rare tumor first described in 1972 by Salm and Sissons, followed shortly by Guccion and Enzinger. This tumor has been considered to be synonymous with the giant cell variant of malignant sarcoma with frequent local recurrence and metastasis. Recently GCT-ST has been described as a distinct entity of relatively benign prognosis, yet lacking marked atypia and pleomorphism, even in the presence of mitotic activity and vascular invasion. Now some authors think that GCT-ST represents the soft tissue analog of giant cell tumor of bone because of their histological and immunohistochemical similarity. Some reports documented these pathological new findings, but clinical case reports with description of imagings and surgery on the basis of these knowledge are very few. The authors describe the clinical, radiological, morphologic and histopathologial features of a case of GCT-ST occurring primarily in the subcutaneous tissue of the thigh with a review of the literature.