In a prospective study of 25 patients, magnetic resonance imaging (MRI) was employed to detect meniscal tears in the symptomatic knee. All patients underwent arthroscopy and 21 underwent double contrast arthrography. When correlated with these two diagnostic procedures MRI produced no false negative results. There were, however, six false positive MRI findings all of which related to the posterior horn of the medial meniscus. MRI appears to be reliable in detecting meniscal tears but long examination times continue to limit its clinical usefulness.