We report a case of reconstruction of radiation ulcer on the chest wall and sternum osteomyelitis using a rectus abdominis musculocutaneous flap. A case of 67-year-old woman, Halsted operation was performed for right breast cancer, 23 years ago. After 4 years, transcatheter arterial injection and radiation therapy was performed to treat recurrence of parasternal lymph nodes. Since then, she had been without recurrence of the tumor, but suffered from repeated scabbing of parasternal skin. In 2009, she suffered from pain, redness and purulent discharge of the wound, and diagnosed with sternum osteomyelitis. She was admitted to our hospital and underwent debridement of sternum, and the resection of surrounding skin. Sixteen days later, reconstruction using a rectus abdominis musculocutaneous flap was performed. Twenty months after the operation, she is well without any evidence of recurrence.