Catheter assembly in which the catheter sleeve is provided with a flexible tip at its distal end for carrying out medical procedures. In order to be able to vary the position of the free end of the flexible tip, a control element is present consisting of an actuating wire. The actuating wire is attached to the free end of the flexible tip and extends externally with respect to the flexible tip, in the direction of the catheter, and then passes through an opening into the inside of the catheter to the proximal end thereof.