PURPOSE: This study was designed to investigate the location of cystic lesions in the greater tuberosity of the humerus and the relationship to rotator cuff tears and age. MATERIALS AND METHODS: A total of 78 patients (age range, 19-82 years; mean age, 51 years) who underwent arthroscopy or open surgery after MR arthrography (MRA) for a painful shoulder were enrolled in the study. The location of the cystic lesions were classified as 'A' for a supraspinatus insertion site, as 'C' for an infraspinatus insertion site, as 'B' for both a supraspinatus and infraspinatus insertion site, as 'BG' for a site posterior to the bicipital groove and as 'P' for a site at the bare area of the humeral head. The location of cystic lesions and supraspinatus and infraspinatus tears were evaluated on MRA. Statistical analyses used the chi-squared test and logistic regression. RESULTS: 'BG' and 'A' cystic lesions were related to the presence of a supraspinatus tear, 'C' cystic lesions were related to the presence of an infraspinatus tear and 'B' cystic lesions were related to the presence of both supraspinatus and infraspinatus tears (p < 0.05). 'P' cystic lesions were not related to the presence of rotator cuff tears. The incidence of cystic lesions increased with age, but with no statistical correlation. CONCLUSION: Cystic lesions at the supraspinatus and infraspinatus insertion sites are useful to predict the presence of a rotator cuff tear, but cystic lesions were not age related.