The diagnosis of rotator cuff tears may be based on clinical examination and MRI. The aim of this study was to define the relative value of these methods. Clinical and MRI diagnoses of 88 shoulders were compared with the intraoperative findings. The correct diagnosis of a posterosuperior rotator cuff rupture was made in 79% of the cases by clinical examination and in 91% of the cases by MRI. For the subscapularis tendon clinical examination corresponded to the intraoperative findings in 73% of the cases versus 59% for MRI. MRI was superior to clinical examination in diagnosing a posterosuperior rotator cuff rupture. For the evaluation of ruptures of the subscapularis tendon, clinical examination was more reliable than MRI. Diagnosis of rotator cuff rupture can most often be obtained by a simple physical examination.