The development of the specialty of thoracic surgery has closely paralleled the evolution of anesthetic tech niques that have allowed for effective, safe isolation of the lungs. A great number of different, often innovative, techniques have been used in the past to achieve lung isolation. This article will review many of these tech niques, but will emphasize the use of modern plastic double-lumen endobronchial tubes (DLT) and bronchial blockers. These are the two most popular ways of isolating the lungs today. The availability of fiberoptic bronchoscopes (FOB) to help confirm accurate place ment of these tubes and blockers has made functional isolation of the lungs not only safe, but relatively easy for any anesthesiologist to perform.