Positional anterior sternoclavicular joint (SCJ) dislocation is relatively rare and needs careful treatment. We report our course of treatment and tips for surgery in a case. The patient was a 16-year-old male outfield baseball player. Three years ago, he had 3 recurrent episodes of right shoulder dislocation. During these injuries, there were forward dislocations of the proximal right clavicle edge accompanied by a creaking sound during the throw acceleration period. Thereafter, the anterior dislocation of the SCJ occurred during the acceleration phase of throwing, and the SCJ naturally repositioned on the shoulder resting position. This situation lingered and he often felt shoulder apprehension during throws, so he opted for surgical treatment just 1 month after the first injury. We performed a modified version of the figure-of-8 technique reported by Wang et al, using the ipsilateral palmaris longus (PL) tendon. The bilateral edge of the PL was attached to a Krackow suture and passed through the bone tunnels opened at the proximal clavicle and proximal sternum so that it became a figure of 8 on the anterior of the SCJ. The stability of the SCJ was confirmed after the surgery.