We reviewed 166 adult patients on long-term haemodialysis, dividing them into three groups according to the presence and type of shoulder pain. The 24 patients in group A, with spontaneous pain related to a supine posture, had been under haemodialysis for significantly longer than the others, and had a much higher incidence of carpal tunnel syndrome. Open or arthroscopic resection of the coracoacromial ligament in 21 shoulders relieved pain during haemodialysis and night pain, and histological examination showed amyloid deposits and inflammatory-cell infiltration in the subacromial bursa in almost all cases, and in the tenosynovium of the bicipital groove in some. We conclude that one type of shoulder pain experienced by patients on long-term haemodialysis is caused by the subacromial impingement of amyloid deposits. This should be distinguished from other types of shoulder pain, because it can be relieved by resection of the coracoacromial ligament