A disposable oxygenating device (2) comprising a body (4,40) and a collapsible bag (16) coupled thereto, the body including first coupling means (6) being couplable to a source of oxygen, second coupling means (10) being couplable to an endotracheal tube, laryngeal mask or the like, a connector (14) to which the bag (16) is connected, an oxygen duct (7) in fluid communication with the first coupling means having an outlet orifice (22) which in use delivers oxygen from the source of oxygen to inflate the bag with oxygen, and an outlet (20,44), the arrangement being such that, in use, during an inspiration cycle, oxygen from the bag passes through the second coupling means (10) and, during an expiration cycle, expiration products pass through the body (2,40) and are expelled through the outlet (20,44).