A catheter is provided with a heated temperature self regulating tip for insertion in an artery to ablate an atherosclerotic plaque obstruction particularly in coronary and peripheral arteries. The heater is located at the distal end of the catheter and has a winding of fine wire around a ferro-magnetic core with the wire being connected via a transmission line to a high frequency constant alternating current source in the megahertz range. The catheter which may or may not employ a guide wire is inserted into and through the lumen of a vessel and guided usually with the assistance of fluoroscopy to the location of the stenosis. The heater is energized to ablate the plaque, the temperature not exceeding a desired temperature as determined by the Curie temperature of the ferromagnetic material.