Background: The technique of arthroscopic subacromial decompression (ASD) is an effective alternative to the open operation. The arthroscopic procedure is technically demanding. Patients and methods: Between January 2016 and February 2018, sixteen male patients, who fulfilled the criteria of the subacromial impingement syndrome, underwent arthroscopy, stability testing under anesthesia and arthroscopic acromioplasty. Pain was the chief complaint of every patient in this study. We used modified UCLA shoulder rating scale for clinical evaluation of the all patients. Pre-operative radiographs included an AP and axillary views added to 30° caudal tilt view or a supraspinatus outlet view were done routinely. MRI of the shoulder was done for all cases. Results: Satisfactory results were achieved in all patients and 6 of them were excellent according to UCLA score. Eight patients had good results and two fair, but no poor results were found in this study up to one year postoperative. Pain relief was the most dramatic benefit but function also improved. The subacromial space of the patients was filled with hypertrophic fibrous bands of bursal stroma, often with fibro-fatty tissue. Hyperemia was often observed. Surface ulcerations were identified on the rotator cuff in 8 cases. Rotator cuff partial tear in 4 cases. Conclusion:  In cases of primary impingement, calcific tendinitis, or partial thickness rotator cuff tears the arthroscopic acromioplasty and decompression, is the procedure of choice provided that no shoulder instability. The right indications and skilled hands, the results are better than the results of open acromioplasty, as the patients recover faster with less risk of deltoid muscle complications.