Clear cell sarcoma (malignant melanoma of soft tissues) is a very rare soft tissue neoplasm. It generally arises in tendons and aponeuroses. Although metastasis of malignant melanoma to bone is not uncommon, primary clear cell sarcoma of bone is an extremely rare neoplasm. To our knowledge five cases have been reported in the English literature. We present a case of primary clear cell sarcoma of bone in a 28-year-old woman arising in the left ninth rib. We treated the patient with total excision of the mass and postoperative radiotherapy. The patient is alive and well without local recurrence or distant metastasis at 33 months after surgery.