We present a new arthroscopic technique for chronic AC joint dislocations with coracoacromial ligament transposition and augmentation by the Tight Rope device (Arthrex, Naples, USA). First the glenohumeral joint is visualised to repair concomitant lesions, such as SLAP lesions, if needed. Once the rotator interval is opened and the coracoid is identified, the arthroscope is moved to an additional anterolateral portal. A 1.5 cm incision is made 2 cm medial to the AC joint. After drilling a 4 mm hole with a cannulated drill through the clavicle and coracoid a Tight Rope is inserted, the clavicule is reduced and stabilized with the implant. The arthroscope is moved to the subacromial space and a partial bursectomy is performed to visualise the CA ligament and lateral clavicle. The CA ligament is armed with a strong braided suture using a Lasso stitch and dissected from the undersurface of the acromion. It is then reattached to the distal part of the clavicle by transosseous suture fixation after abrasion of its undersurface. Although this combined arthroscopic procedure of AC joint augmentation with a Tight Rope combined with a ligament transposition is technically demanding, it is a safe method to reconstruct the coracoclavicular ligaments and achieve a sufficient reduction of the clavicle without the need of further implant removal or autologous tendon transplantation.