The records of 300 patients with penetrating wounds of the chest were studied. Asymptomatic patients may have unsuspected gross findings requiring immediate intervention; minimal amounts of air or fluid may be overlooked if meticulous details of technique are not observed; assumption that a penetrating wound necessarily causes pneumothorax or hemothorax may even lead to unnecessary surgery if x-ray examination is not carried out. If as the result of hemorrhage or pneumothorax the patient is in critical condition when first seen, emergency surgical intervention cannot be deferred for an initial x-ray examination. The role of radiology in such cases is to check on the effectiveness of treatment and anticipate the possible complications.