In no musculoskeletal area has the marked growth and expansion of interest in the application of magnetic resonance imaging (MRI) been more evident than in assessment of articular disorders of the knee.1–27The high accuracy of the method, coupled with its noninvasive nature and lack of operator dependence, has allowed MRI to challenge and indeed rapidly replace arthrography in many institutions. In addition to evaluation of meniscal and ligamentous abnormalities, MRI has demonstrated a markedly expanded diagnostic capacity to include a wide spectrum of abnormalities that may previously have escaped early detection with the use of arthrography or arthroscopy. It is anticipated that future technologic advances will further the diagnostic efficacy of the technique and its ultimate contribution to patient management.This article is based on our experience with more than 3,500 MR examinations of the knee. The discussion will emphasize salient aspects of technique, normal and pathologic anatomy, and potential pitfalls in interpretation of the examination. The accuracy of the method and its relation to other diagnostic techniques will be addressed.