Forty-two patients with benign as well as malignant bone tumours or with tumour-like lesions of bone were evaluated using MR tomography. The appropriate choice of examination parameters is an essential prerequisite for the adequate visualisation and the definitive verification of the presence of a tumour. By means of its multi-planar display, MR provides definite advantages in the determination of tumour localisation and extension as well as in differentiating intra-tumoural haemorrhage from surrounding, non-involved tissue. In addition, the clear delineation of neighbouring structures such as muscular compartments and blood vessels achieved in MR can be useful in the planning of an eventual surgical approach. This new technique has proved itself superior to other available imaging modalities in the differentiation of residual or recurrent tumour from post-operative changes. A characterisation of the nature or histology of a suspicious lesion on the basis of relaxation-times or signal intensities, however, is not yet possible.