[en] The relatively recent use in HEP of the Kalman filtering and smoothing technique for the reconstruction of single tracks through gaseous detectors interspaced by heavy materials, is shown to work and to give even better results than other more classic techniques. However, fine tuning of the computer implementation has to be done carefully as well as respecting the mathematical constraints. The feasibility of the Kalman method in heavy materials here demonstrated may lead to the development of a general software package for the reconstruction of single tracks in HEP detectors. (orig.)