Posterior bone grafting represents an emerging therapeutic approach for addressing recurrent instability in the posterior shoulder, particularly when coupled with substantial glenoid bone loss. Although not as prevalent as anterior instability, recent years have witnessed the development of numerous open and arthroscopic bony reconstruction methods. A technical gold standard for posterior bone grafting remains undefined, leading to ongoing advancements in bone grafting techniques. In response to past challenges associated with screw fixation, metal-free arthroscopic fixation procedures have been introduced to the realm of bone grafting. These metal-free methods often entail intricate transglenoid drilling, which poses potential surgical complexities and risks to both posterior and anterior soft tissues, as well as neurovascular structures. Therefore, we introduce an arthroscopic approach to posterior bone grafting using PEEK (polyether ether ketone) anchors with interconnected sutures and a scapular spine autograft. This method overcomes previous hurdles by facilitating the restoration of the posterior glenoid bone stock with precise positioning and secure fixation of the tricortical scapular spine bone autograft.