Magnetic resonance imaging has already become a most valuable imaging modality in the diagstic work-up of musculoskeletal neoplasms. While high accuracy of MRI for staging purposes has been proven, we will focus in this mograph on the characterization of primary bone and soft tissue tumors by MRI. The major purpose of this mograph is to provide an atlas of magnetic resonance features of primary bone and soft tissue tumors for radiologists, orthopedic surgeons and physiotherapists. The results presented are based on investigations of 94 primary bone and soft tissue tumors and mimicking conditions by magnetic resonance imaging. Although the scale of the material allows for statistical handling, the number of patients per subgroup is too small to come to definite conclusions. We will therefore limit ourselves to the description of and comments on a great number of cases to illustrate the diagstic potential of this new imaging modality. We would like to thank the anymous cooperators: referring clinicians, pathologists, nurses, technicians and secretaries whose help enabled us to present this mograph. We would also like to express our gratitude to the firms Siemens AG and Schering AG for technical support.