INTRODUCTION: brachial plexus injuries may cause devastating deficits in the upper extremity, with functional, occupational, and social sequelae for lifetime. Within nerve reconstruction treatments, contralateral C7 (CC7) nerve transfer is one of the most encouraging because of its great power of neurotization due to its more myelinated nerve fibers,(1) wide variety of possible functional recovery objectives, and even different surgical techniques, as the retroesophagus route described to shorten the distance between the C7 root and nerve target often obviating the need for nerve grafts.(2) However, its effectiveness and donor morbidity reported by current literature are still confusing with very little reports coming from developing countries that as we know may carry significant access barriers and impact final results.(3) Our purpose is to describe in detail our technique and share our experience employing it. METHODS: Our series consists of 61 patients with preganglionic upper brachial plexus injury who underwent CC7 nerve transfer using a retroesophagus tunneling technique in a center from Medellin (Colombia) since January 2000 with a minimum of follow-up of 5 years and a maximum of 17 years, with a systematic electrodiagnostic and physical evaluation using Medical Research Council–based (MRC) outcome scale for motor function in all cases. RESULTS: There was a total of 61 patients, from which 55 (90.2%) achieved at least MRC grade M3 to M4 motor recovery for shoulder abduction or flexion, or elbow flexion, and 6 patients (9,8%) only obtained MRC grade M2 motor recovery in shoulder abduction. We observed sensitive recovery in some patients but it was not reproducible in most patients from our series. Regarding donor morbidity, we had a case of neuropraxia for wrist and finger extension, and sensory symptoms in 3 patients, that resolved spontaneously. Finally, respecting complications, dysphagia was identified in 15 patients, but we performed esophagus studies without finding significant changes in their anatomy; we also had a case of subclavian vein trauma requiring reconstruction with a saphenous graft and a patient that required to be explored because of a hematoma. CONCLUSION: Traumatic injuries to the brachial plexus tend to be very disabling, the surgeon can directly influence the overall result but it is unpredictable to ensure a functional restoration; access to physical rehabilitation and patient cooperation are also critical definitive factors, especially in cases of nerve transfers. Despite all this, today we can be more optimistic than before regarding the treatment of this pathology even in developing countries, and the CC7 nerve transfer, using a retro esophagus tunnel, is a safe and effective manner for motor and sensitive restoration. References: 1. Chuang DC. Neurotization procedures for brachial plexus injuries. Hand Clin. 1995;11(4):633-645. 2. Mcguiness CN, Kay SP. The prespinal route in contralateral C7 nerve root transfer for brachial plexus avulsion injuries. J Hand Surg Br. 2002;27(2):159-160. doi:10.1054/jhsb.2001.0665 3. Yang G, Chang KW, Chung KC. A Systematic Review of Contralateral C7 Transfer for the Treatment of Traumatic Brachial Plexus Injury: Part 1. Overall Outcomes. Plast Reconstr Surg. 2015;136(4):794-809. doi:10.1097/PRS.0000000000001494