A method is described for determining the position of a mobile station in a cellular network. It comprises the steps of providing (210) a plurality of radio parameters of the mobile station measured when the mobile station is located at a certain position and estimating (250) the position of the mobile station by comparing the measured radio parameters to a plurality of vectors of radio parameters in a positioning matrix, wherein each of the plurality of vectors is linked to positioning coordinates. The positioning matrix has been previously built based on measurement reports of a plurality of radio parameters of mobile stations, measured when the mobile stations are located at a certain position and positioning coordinates of the mobile stations determined with the aid of an external positioning system, such as GPS. Vectors of the measured radio parameters are created in the positioning matrix and linked to the positioning coordinates.
