Thoracic Surgery is that discipline of medicine, which involves the invasive treatment of organs, which are inside the rib cage or the thorax, or the space between the diaphragm and the neck. The main organs inside the thorax are the lungs and the heart. But other organs, which, come under the purview of Thoracic Surgery, are the esophagus, the trachea or windpipe, the pleura and the chest wall. Normally this discipline, excludes the heart but in recent times, the heart is also included and this branch is known as cardio thoracic surgery. The doctor who performs such surgeries are known as thoracic surgeons or cardio thoracic surgeons.

The conditions that require cardio thoracic surgeries are esophageal cancer, lung cancer, chest wall cancer, coronary artery disease, abnormalities of the valves of the heart, birth defects of the chest and heart, any tumors in the organs found in the chest cavity, drainage of abscess in the lung, air-leak syndromes, a situation, where, air leaks into the pleural space and forces the lungs to collapse, thereby causing severe breathlessness and most importantly, transplantation of the heart and lungs. These surgeons also perform thoracocentesis, a procedure by which any fluid collection is drained from the chest cavity for diagnostic as well as therapeutic purposes.