Several of the features of magnetic resonance imaging (MRI) are advantageous for diagnostic examination of the musculoskeletal system. For example, the excellent depiction of bone marrow makes it a very sensitive method for identifying trauma, tumor, ischemia and infection of the marrow space. In addition, the high-contrast discrimination of soft tissues and the ability to make thin-section images in any plane allows for the depiction of abnormalities involving the muscles, ligaments, tendons, and neurovascular structures. The major disadvantages are the nonspecificity of many of the findings, the high cost of examinations, and the limited number of available MRI units. MRI is most appropriately utilized when it can be expected to provide diagnostic information not available from less-expensive noninvasive diagnostic methods and when the results of the examination may significantly affect patient management. To get the most out of the examination, it should be performed and interpreted with knowledge of clinical findings and results of other imaging tests, especially plain roentgenograms. To date, MRI has proved to be most useful for the evaluation of the spine, shoulder, hip, and knee.