Arthroscopic subacromial decompression (ASAD) is becoming a widely performed surgical procedure of the shoulder. The technique has evolved from open anterior acromioplasty as described by Neer,1,2 Hawkins et al,3,4 Rockwood,5 and Bigliani et al.6 The transition from open to arthroscopic technique entails a definite learning curve and should not be underestimated. This chapter focuses on the tec...