Abstract: The invention provides a laser catheter for pinpointed application of laser light on the walls of intracorporal vessels, having a ring-shaped arrangement of optical fibers which surround a central longitudinal channel. A stop element at the distal region of the laser catheter widens the outer circumference, through which the optical fibers pass in beam direction. At the distal catheter tip, the fibers form a planar, ring-shaped light, exit area. The longitudinal channel of the laser catheter is provided at its distal end with a perforated member which is disposed at a short distance from the plane, ring-shaped light exit area in a direction opposite the beam direction. A second element is provided which is attached to a vessel wall as a spacer and engages, during the laser light application procedure with the element widening the circumference of the light catheter.