BACKGROUND; Benign fibrous histiocytoma (BFH) of bone is a very rare tumor, and almost all reported cases were diagnosed after surgical resection by histologic examination. We report a case in which cytologic features of BFH of bone were established preoperatively by fine needle aspiration (FNA). To the best of our knowledge, FNA findings of BFH of bone have not been previously reported. A 30-year-old man presented with pain in the right knee of 3 days' duration. Radiographs of the distal femur showed a lytic lesion. FNA biopsy followed by cytologic examination revealed highly cellular smears with spindle-shaped cells arranged in sheets, papillary fronds and storiform pattern. These cells had a moderate amount of cytoplasm and round to elongated nuclei with inconspicuous nucleoli. Multinucleate giant cells were occasionally seen. A cytologic diagnosis of Giant cell tumor of bone with a BFH component was rendered. Histology revealed a pure BFH of bone. The current case reveals the cytomorphologic features of BFH of bone. Cytology may permit the preoperative recognition of the lesion, allowing a more sound therapeutic approach.