Pulmonary inflammatory myofibroblastic tumor is an uncommon, benign solid tumor of the chest that mostly affects children. We present a 7-year-old body who suffered from cough. The chest radiograph and chest CT showed a rapid growing mass in left upper lobe. Based on histopathologic examination, pulmonary inflammatory myofibroblastic tumor was diagnosed; although rare, it is the most frequent primary lung tumor in childhood.