The typical chest computed tomography (CT) finding of the arc welders is ill-defined micronodules diffusely distributed in the lung. We report a rare case of tracheobronchial foreign body in welder without the history of allotriophagy and foreign body aspiration. We used the CT and mineralogical analysis in diagnosis and the flexible fiberoptic bronchoscope in therapy. The CT showed bronchiectasis with pulmonary infiltration of the right lower lobe and high-density shadow in the basal bronchus of the right lower lobe. The foreign bodies were removed by a fibreoptic bronchoscope. Semiquantitative chemical analyses showed that the constituent of foreign body was similar to the dregs which were collected in the same garage. This is an unusual case of the welding-related respiratory diseases, which is different from Welder's siderosis and broncholith.