A 40-year-old man who had been surgically treated for the fracture of the right humerus with two Kirschner wires (K-wires) complained of chest pain and difficulty in breathing at fourth day after surgery and visited our hospital. Chest radiography revealed dislocation of the K-wire and right pneumothorax. Video-assisted thoracic surgery( VATS) was performed immediately, and the K-wire was removed safely.