Laser application for lung cancer was introduced early in the 1980s to remove malignant obstructive lesion of the lower trachea and main bronchi. The main indication was in patients with inoperable central lung cancer. Intraoperative use of Thermal laser began later. In the early and mid-1980s, Photodynamic Therapy (PDT) became available. In this chapter, the laser and laser light physics are briefly described prior to their applications and indications in lung cancer. The Nd;YAG laser, which is the most commonly employed thermal laser and its effects on lung tissue, is described, followed by its brief indication in the clinical practice of lung cancer. The principle and mechanisms of PDT in destroying cancer tissues have also been discussed in this chapter. PDT indications in a variety of lung cancer are also discussed to some extent.