Posterior Hill-Sachs humeral defects are present in 80% to 100% of cases of anterior shoulder dislocation and are a factor in recurrent instability. Several techniques have been described to fill the defect and avoid recurrence. We developed a percutaneous technique to fill the newly created defect in which a percutaneous balloon, analogous to the one used in vertebral kyphoplasty, is used to reduce the defect, which is then filled with calcium phosphate cement. One patient with an acute anterior dislocation of the shoulder with no previous history was treated using this method. Early imaging results showed adequate reduction of the defect and no cement resorption. The patient was followed for 12 months; he had normal function of the shoulder and no recurrent dislocation. Shoulder computed tomography (CT) arthrography with contrast after 3 months showed an intact capsule and no recurrence of the defect. While this technique is certainly in its infancy, we have demonstrated that emergency reduction of the defect in acute first occurrence anterior shoulder dislocation is feasible, helps to restore normal anatomy of the humeral head and leads to good clinical results. Whether it can improve clinical results and prevent recurrent shoulder dislocation remains to be evaluated.