Ninety cases of malignant fibrous histiocytoma (MFH) of bone are reported. An analysis is presented with regard to sex, age, site, symptoms, radiography, macroscopic, and microscopic features. The staging was assessed according to the following classification: I B: 3 cases; II A: 11 cases; II B: 66 cases; III: 10 cases. Among nonmetastatic patients, 68 had surgical treatment (adequate, 46; inadequate, 22); 8 had radiotherapy, and 3 refused any treatment. Among surgically treated patients, 20 had adjuvant chemotherapy, also. Follow-up information was obtained in all cases. Overall survival rates were 34% at 5 years, and 28% at 10 years. Surgery alone did not appear to be successful (5-year survival, 28%). Adjuvant chemotherapy improved the survival rate only in patients who underwent adequate surgery (5-year survival, 57%). The recurrence rate after surgical treatment was high (31%) with significant differences after inadequate (64%), wide (19%), or radical (6.5%) surgical treatment. Adjuvant chemotherapy was ineffective in preventing local recurrence. Radiation therapy effected a clinical cure in three cases; the authors believe that radiation therapy has to be used only in inoperable tumors.