Bacillus-Calmette-Guérin (BCG) vaccination often results in local adverse effects; however, serious or long-term complications are rare. The involvement of sternum among skeletal BCG osteomyelitis is a rarely seen complication of BCG vaccination. Such a complication may confuse with a chest wall tumor and a surgical intervention may be needed for the definite diagnosis. A 9-month-old infant who had a parasternal cold abscess in the anterior chest wall and sternal osteomyelitis of tuberculosis in the late period of BCG vaccination of whom the etiological diagnosis was histopathologically confirmed after surgery is presented and the preoperative diagnostic problems are discussed.