The management of giant cell tumor of the proximal humerus that extends to the joint is challenging. Here, we report a case of proximal humerus giant cell tumor with cortical bone destruction extending to the shoulder joint. Pre-operative selective arterial embolization induced peripheral tumor ossification. Subsequently, the lesion was removed by intralesional curettage, and the cavity was filled with cement. Macroscopically, the inner wall of the cavity was found to be lined with a thick fibrous membrane. Histologically, massive fibrosis and resultant remodeling of the destroyed cortical bone were induced, which was consistent with the peripheral ossification on the plain radiograph. We believe that selective arterial embolization can be an effective neoadjuvant therapy for giant cell tumors of the extremities, especially for tumors with large cortical defects or joint involvement.