A method is disclosed for fixing at least one location in an examination field (9) with respect to a coordinate system (13). The method includes determining, in response to a request (65), coordinates of a first location (59) as a first coordinate set (x, y, z) allocated to the first location (59). A first recording and a second recording of topological data (69) in a spatially extended area around the first location (59) in the examination field (9) are obtained. The first and second recordings are compared to determine a displacement (&Dgr;x, &Dgr;y, &Dgr;z) of the first location (59) of the examination field (9) with respect to the coordinate system (13), the coordinates of the first coordinate set (x, y, z) allocated to the first location (59) are changed dependent upon the determined displacement (&Dgr;x, &Dgr;y, &Dgr;z) such that the changed coordinates substantially correspond to the coordinates of the first location (59) in the examination field (9) after the displacement thereof.