In a method for correctly geometrically assigning x-ray images of a patient an optically operating recording device is attached to an x-ray device generating the x-ray images. A dimensionally stable marker surface which can be optically detected by the recording device and defines a reference system is fixed to the patient in a fixed relative position. The x-ray device is brought into a first and second recording position such that the recording device is directed toward the marker surface. In a recording position the x-ray device produces a first and second x-ray image of the patient and the recording device produces a first and second recording of the marker surface. The respective geometric position of the first and second x-ray image is determined in the reference system from the recordings. The first and second x-ray images are correctly geometrically assigned to one another in accordance with their position.
