We evaluated an all arthroscopic technique for treating suprascapular nerve entrapment by cyst formation in the spinoglenoid notch. Eight patients showed positive MRI and EMG findings with clinical sign of weakness and pain and with atrophy of the muscle. All patients underwent an all-arthroscopic procedure. The patients were evaluated preoperatively and 6 weeks and 3 months postoperatively and for the latest follow-up by clinical examination, MRI, and EMG. All patients improved in terms of pain, strength, and function. We found six superior labrum anterior and posterior (SLAP) lesions. In these patients the cyst was drained, and the SLAP lesion was repaired. In two patients there was no communication between the joint and the cyst, and therefore capsulotomy was performed and left open. The results of our study show that arthroscopic decompression of the suprascapular nerve can be achieved by an all arthroscopic technique if the cyst formation is located at the spinoglenoid notch.