Abstract: A single lumen endobronchial tube is provided which comprises a tube for location in the tracheo-bronchial tree of a patient. The tube has an endotracheal portion for location in the trachea and an endobronchial portion for location in one of the bronchi. The endobronchial portion communicates with the endotracheal portion, has an open end and a port spaced from the open end. Means such as inflatable cuffs are provided for locating the tube in position in a patient so that the open end of the endobronchial portion of the tube is in one bronchus while the port is in communication with the other bronchus. A further inflatable cuff is located in the lumen between the port and the open end to close off and isolate the endobronchial portion and that bronchus. The port remains in communication with the other bronchus whether or not the other bronchus is isolated.