Coracoacromial ligaments from 133 operation specimens were examined histomorphologically near their acromial attachments. 85% showed signs of moderate to severe degeneration, 67% to 85% chondroid metaplasia near the origin. No significant differences were found between specimens brought to operation for the three diseases mentioned. It is therefore concluded that an intermittent local pressure on the origin of the ligament is present in these diseases, and this can lead to chondroid changes near its acromial attachment.