We report the results of arthroscopic subacromial decompression and debridement of the rotator cuff for chronic small- and medium-sized tears in 114 patients (118 shoulders) between two and five years after surgery. The mean Constant score was improved to 69.8, and 88 shoulders (74.6%) had a satisfactory outcome. Of patients under the age of 60 years the outcome was satisfactory in 59.3%, and in those over 60 years, in 87.5% (p < 0.001). An unsatisfactory outcome was related to manual work (p < 0.001) and a duration of symptoms of more than 12 months (p < 0.05). The outcome was not related to the size of the tear, the muscles involved or biceps pathology. Further surgery was required in 25 patients after a mean of 13.7 months (3 to 35); ten tears had progressed in size, but none became irreparable. There was no relationship between the increase in the size of the tear and its initial size, the muscles involved or the presence of biceps pathology. No tear became smaller with time