The cubital tunnel syndrome is one of the most common entrapment neuropathy of the upper limb. The ulnar nerve can be compressed in the oteofibrous tunnel by the bone structures, the Osborne's ligament, the fascia of the ulnar flexor muscle of the carpus or of the aponeurosis of the deep flexor of the fingers. Pressure values in the cubital tunnel >50 mm Hg induce blocking of intraneural circulation with electrodiagnostic modifications, clinical signs and histological changes including demyelinazion of the nerve proximal to the cubital tunnel. Surgery becomes essential in case of failure of conservative and physical therapy. Various surgical techniques have been described in the literature for the treatment of the ulnar neuropathy at the elbow. In this paper the authors report a new endoscopic technique for the treatment of ulnar nerve entrapment at the elbow which requires respect of specific electrodiagnostic and clinical criteria of inclusion. The restored joint active motion following elbow arthroscopy in osteoarthritis can induce or get worse a ulnar nerve neuropathy; endoscopy neurolysis is essential to remove perineural adherences and reduces the nerve stress. Immediate well-being of the patient, lesser invasiveness and minimum vascular complications are clear advantages of the endoscopic approach, while the treatment of the pathologies proximal and distal to the Struther's arcade is a limit of the technique.