A device (S) for generating focussed acoustic pressure or shock waves for therapeutical purposes, in particular for destroying concretions, stones, etc. in the body, has a pressure or shock wave source, a unit for locating the concretion to be destroyed having an X-ray system with an aiming arrangement that can project a figure by means of the X-ray radiation of the X-ray source (Q) on a X-ray receiver (E), and a patient reception unit. The device is characterized by the aiming arrangement projecting on the X-ray receiver a figure that is independent of the location of the X-ray source and receiver, and by the fact that the connecting line between the X-ray source and the centre of the projected figure always extends through a fixed point in space outside the aiming arrangement.