A thoracic drainage system (1), comprising a drainage catheter (10) that is adapted to be inserted in the pleural space of a patient in order to drain air and/or liquids that are present in the pleural space, and a drain tube (50), which is connected to the drainage catheter (10) by means of a connector (30) which is adapted to make the air and/or the drained liquids flow out via the drainage catheter (10) to a collection chamber (60)； the drainage catheter (10) comprises, at its distal end (11), a plurality of longitudinally extended channels (13, 14) which are open radially toward the outside of the drainage catheter (10) and are adapted to drain the liquids that are present in the pleural space, and, at its proximal end (12), at least one port (15, 150) for the drainage of the liquids, in which the open channels (13, 14) merge, the drainage catheter (10) comprising a port (16) for the drainage of the air that is present in the pleural space, the port (16) for the drainage of the air comprising, at the distal end (11) of the drainage catheter (10), a plurality of radial holes (17) adapted to be crossed by the air that is present in the pleural space, the drain tube (50) comprising, substantially along its entire longitudinal extension, a first outflow port (51) which is connected, by means of the connector (30), to the at least one port (15, 150) for the drainage of the liquids and a second outflow port (52) which is connected, by means of the connector (30), to the port (16) for the drainage of the air.L'invention concerne un système de drainage thoracique (1), comprenant un cathéter de drainage (10) qui est conçu pour être introduit dans l'espace pleural d'un patient afin de drainer l'air et/ou les liquides qui sont présents dans l'espace pleural, et un tube de drainage (50), qui est relié au cathéter de drainage (10) au moyen d'un raccord (30) qui est conçu pour faire sortir l'air et/ou les liquides drainés par l'intermédiaire du cathéter de drainage (10) vers
