MR was performed in 41 patients suffering from benign and malignant bone and soft-tissue tumor before and after intravenous injection of the paramagnetic agent gadolinium-DTPA (Gd-DTPA). Using T1-weighted parameters, the contrast of tumor tissue versus muscle could be increased by Gd-DTPA. Thus, extraosseous extension as well as infiltration of the spinal canal was depicted to better advantage. Inhomogeneities were visualized with higher frequency and improved contrast. In several instances, there was no differentiation between tumor and adjacent edema without application of Gd-DTPA. T2-weighted images without Gd-DTPA exhibited higher contrast as compared to T1-weighted images after Gd-DTPA. The contrast to tumor tissue versus fat and bone marrow respectively was reduced after applying Gd-DTPA. Thus, for the evaluation of bone marrow infiltration, T1-weighted images without Gd-DTPA proved to be indispensable.