Since 1982 a sonographic technique has been devised to evaluate the integrity of the rotator cuff. In a series of 139 shoulders in 134 consecutive patients without prior surgery, sonographic results were correlated with surgical findings and/or arthrography. When sonography was compared with surgical findings (n = 90 shoulders), the overall accuracy was 95%. The sonographic diagnosis was the same as the arthrographic diagnosis in 91% of the cases (n = 50). Cuff lesions were also created in two cadavers, and images were made to confirm sonographic appearances. Because in the authors' experience sonography is accurate, safe, painless, rapid, and inexpensive, it has now been adopted as the primary study for the examination of the rotator cuff at the authors' institution. Arthrography is recommended in cases in which sonography is negative but there is significant clinical evidence of rotator cuff tear.