Malignant fibrous histiocytoma of bone (MFH) is a histologically defined bone tumour, which can be distinguished from osteo- and fibrosarcomas. The present paper deals with the question whether MFH can be distinguished from these tumours on clinical grounds. One hundred and fifty-seven previously published, and four additional cases have been analysed with respect to their localisation and their biological, clinical and radiological behaviour and their prognosis. It was found that MFH can be distinguished from osteosarcomas on clinical grounds and that this is significant in relation to treatment; its distinction from fibro-sarcomas is clinically not justified.