Primary sternal chondrosarcoma is a rare malignant tumor that is refractory to chemotherapy and radiation. Effective therapy is radical resection of the tumor. We present two patients with primary sternal chondrosarcoma who underwent a radical resection of the lower half of the sternum and bilateral ribs, followed by reconstruction with 2 sheets of polypropylene mesh layered orthogonally. The patients have maintained almost the same pulmonary function as preoperative values, with stability of the chest wall. Although there are various ways to reconstruct the anterior chest wall, reconstruction with polypropylene mesh layered orthogonally is an easy-to-use and sufficient method.