The purpose of this study was to assess the diagnostic accuracy of the Neer and Hawkins impingement signs for the diagnosis of subacromial bursitis or rotator cuff pathosis. Eighty-five consecutive patients undergoing shoulder arthroscopy by a single surgeon were documented prospectively for the positive and negative clinical and arthroscopic pathologic findings. The Neer sign was found to have a sensitivity of 75% for the appearance suggestive of subacromial bursitis; this compared with 92% for the Hawkins sign. For rotator cuff tearing, the sensitivity of the Neer sign was 85% and the sensitivity of the Hawkins sign was 88%. Specificity and positive predictive values for the two tests were low, being not much higher than pretest probability. The two tests had a high negative predictive value (96% for bursitis, 90% for rotator cuff tearing) when they were combined. The results are compared with those reported in the literature. We conclude that the Neer and Hawkins signs are sensitive for appearances suggestive of subacromial bursitis and rotator cuff partial or complete tearing with a high negative predictive value. However, they lack specificity in comparison with arthroscopic findings.