A catheter assembly 102 for the provision and/or removal of blood or other fluids has a catheter hub 4 containing a chamber (12, figure 1) with a female luer connection at its proximal end 40 and at its distal end a catheter 10 attached to the hub. An extension tube 62 opens into the chamber from one side and its other end couples to an infusion device via a connector 64. A hypodermic needle 30 is mounted in a separate hub 20 and can extend through the chamber and through the catheter. A guard shields the needle with two arms extending distally (figure 8). Inside the chamber is a valve assembly 70 having two separate valve members. The first closes the distal end of the extension tube and opens under the action of a pressurised fluid within the tube； the second is a twoÂway valve preventing the axial flow of fluid through the chamber and is preferably a selfsealing elastomeric disc with slits in.
