BACKGROUND Management of high grade acute acromioclavicular (AC) joint dislocation is considered a surgical dilemma. Open methods of fixation are the gold standard but the morbidities are frequent. The goal of this study was to evaluate the results of arthroscopic fixation of acute high grade (AC) joint dislocation. METHODS A series of 24 patients with acute high grade acromioclavicular joint dislocation were fixed arthroscopically using TightRope device. The study was done between February 2013 and February 2017. The functional outcomes were assessed using Constant-Murley score and University of California at Los Angeles shoulder (UCLA) scale. The preoperative and postoperative means of coraco-clavicular distance were calculated and used for radiological assessment. P-value < o.o5 was statistically significant. RESULTS The mean followed up time was 23.25 ± 7.1 (12-35) months. There was highly significant improvement in the Constant-Murley score and (UCLA) scale at the end of the follow up period. The coraco-clavicular distance was improved from 21.7 ± 3.1 mm preoperative to 10.17 ± 2.3 mm postoperative. There were two complications, one case had over correction and the other had mild transient post-operative burning pain along the course of ulnar nerve. CONCLUSIONS Arthroscopic fixation of acute high grade (AC) joint dislocation is safe, minimally invasive technique with satisfactory functional outcomes and low morbidities provided that it is done by surgeons skilled in shoulder arthroscopy.