Abstract: The invention relates to an endocavitary cardiac stimulation probe. This probe comprises a tubular electrode connected to a cardiac stimulator by a flexible tubular insulated conductor. A harpoon, in solid biologically compatible material which can be resorbed during a period of the order of three weeks to three months, is mounted to slide in the tubular electrode in such manner that it can be extracted therefrom with a view to its being implanted in the endocavitary wall, by means of a thrust transmitted through the tubular conductor. This probe offers the advantage of being immobilized first by the harpoon and then, after resorption of the harpoon, by the natural formation of fibrose around the electrode.