Computed tomography-guided percutaneous transthoracic fine-needle aspiration biopsy of lung lesions is a well known diagnostic technique. Nevertheless, it has some complications; such as pneumothorax, intraparenchymal hemorrhage and hemoptysis, which are not rare. Air embolism is one of the rare but potentially fetal complications of this procedure. Herein, we report the case of a 69-year-old male, in which case of systemic air embolism developed after the performance of lung biopsy. Early diagnosis and prompt oxygen therapy is crucial for patient's survival so careful reviewing of the obtained computed tomography images during the biopsy may prevent a missing systemic air embolism and provide an adequate therapy.