To determine the position and orientation of an object in a x-ray image the x-ray image is initially pre-processed. A three-dimensional template (data record) of the object based on the known constructional features of the object is created. Three parameters for the position and for the orientation respectively are modified iteratively. The three-dimensional template with the parameters for position and orientation is projected in each case onto a two-dimensional plane and the created image is compared on the basis of the generation of a degree of similarity with the pre-processed x-ray image.