Aggressive combined resections were carried out, on 24 lung cancer cases which showed invasion into surrounding organs. Those cases with wide infiltration of the ribs, and into surrounding intercostal tissues, and for those with invasion to diaphragm, the outcome of the operations was rather poor but, for those with invasion in pericardium and left atrium, fairly favorable results were obtained. These present results indicated that aggressive resections of adjacent organs is to be recommended for cases without N 2 infiltration. Experiences from these operations have taught us the importance and useful of diagnosis of the status of invasion of the tumor, during the operation by ultrasonogram (IUS), with direct contact of the probe to the thoracic wall or mediastinal organs, to discriminate the areas of chest wall and mediastinal organs that require resections. This method, in combination with esophagus ultrasonic endoscopy (EUS), enabled defining the infiltrated areas with accuracy far exceeding that obtained by tactile examination. Techniques of, and observations obtained by these examination methods are presented.