Despite the more general use of sputum cytology and bronchoscopy, the most available, least expensive, and simplest method for the detection of a malignant lesion in the lung, when it is small, is roentgen examination.4 A single posteroanterior roentgenogram made in inspiration is an effective method for finding cases in their presymptomatic stage. An additional number of small lesions would be discovered if it were possible to add a second film so that stereoscopic or posteroanterior and lateral views would be made in each case. Obviously, additional roentgenograms, such as those made in the oblique positions, apical lordosis, and in expiration would increase the productivity, but it is impractical to make such elaborate examinations in asymptomatic individuals. The presence of symptoms which are at all suggestive of carcinoma of the lung should lead to such a thorough investigation, to which should be added body-section roentgenography and, if needed, bronchography.