Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of vascularized ulnar nerve transposition un- der myofascia for cubital tunnel syndrome. [Methods] The nutritional vessels and the length of the ulnar nerve were measured on 6 adult up- per limbs with red latex perfusion in the artery, and then the operation was designed. A total of 20 patients with mild cubital tunnel syndrome were divided into two groups with 10 cases in each group. The patients in the two groups received vascularized ulnar nerve transposition un- der myofascia, or traditional ulnar nerve transposition, respectively. In the vascularized group, the ulnar nerve and its associated vessels were freed and protected during the operation, and the ulnar nerve with associated vessels were moved to the anterior position under myofascial. [Results] All the patients had operation performed in 30~45 min, with good incisions healing. All patients were followed up for more than 6 months, with a mean of recovery of sensation about 3.6 months, while a mean of recovery of hand muscle strength about 4.2 months. Regard- ing electrophysiological tests, the sensory nerve conduction velocity (SCV) and motor nerve conduction velocity (MCV) significantly im- proved in both groups 6 months postoperatively compared with those preoperatively (P＜0.05). Although there was no significant difference in SCV and MCV between the two groups before surgery (P＞0.05), the vascularized group proved significantly superior to the traditional group in terms of SCV [(50.7±6.7) m/s vs (47.6±5.3) m/s, P=0.049] and the MCV [(52.5±3.8) m/s vs (48.4±3.1) m/s, P＜0.001]. [Conclusion] The technique of vascularized ulnar nerve transposition under myofascia is simple and feasible, which can improve the clinical outcomes.