Eighty patients treated with arthroscopic decompression for shoulder impingement syndrome were enrolled in this study to determine the impact of additional radiofrequency based plasma microtenotomy. Significant reductions were observed in pain in both groups by the third postoperative week and range of motion was better in all measurements by 1 year. No differences between the two groups were observed for any outcome measure at any time point. Decompression surgery is an effective treatment for patients with shoulder impingement syndrome but radiofrequency based plasma microtenotomy added no additional benefits.