Abstract: Intra-aortic balloon apparatus is disclosed including a single chamber balloon sealably attached to the end of a catheter for non-surgical insertion into the aorta through the skin as by the standard Seldinger technique. In the preferred embodiment, the extreme end of the balloon is fixedly attached to one end of a separate substantially circumferentially rigid but longitudinally flexible tube open at both ends and disposed within and extending the length of the catheter. The opposite end of the tube remote from the balloon is fixedly attached to means for effecting rotation of the tube within the catheter and thereby result in controlled sequential wrapping and unwrapping of the balloon about the tube. In use, the balloon is pumped in conventional manner via the catheter and access through the tube is provided to the interior of the aorta at the extreme end of the balloon.