Thirty-nine consecutive patients referred for shoulder arthrography underwent shoulder sonography to determine the ability of sonography to detect rotator cuff tears. Fifteen patients had arthrographically proven rotator cuff tears. Of these, 14 were detected by sonography, for a sensitivity of 93%. The three sonographic criteria indicative of rotator cuff tear were (1) discontinuity in the normal homogeneous echogenicity of the rotator cuff; (2) replacement of the normal homogeneous echogenicity by a central echogenic band; and (3) nonvisualization of the cuff. Twenty patients had normal sonographic examinations, 19 of which were normal by arthrography. Therefore, the predictive value of a negative sonogram was 95%. On the basis of these findings, sonography can provide a noninvasive means of screening patients with suspected rotator cuff tears.