A 46-year-old woman with giant chondrosarcoma of the sternum underwent wide full-thickness resection of the anterior chest wall, which included the pericardium and lung. The free rectus abdominus musculocutaneous flap was transplanted onto prosthetic meshes placed in two layers. While stability and esthetic effect were both good, the subsequent infection in the space between the two meshes prolonged for one month. As a result, the space was closed with an omentum flap. As a consequence, we recommend one-stage omentopexy to prevent the space problem between the two meshes.