Tindioxide coatings with different fluorine-doping have been produced by spray pyrolysis. The coatings have been analysed by spectrophotometry, Hall-effect measurements, X-ray diffraction and electron probe microanalysis. It is shown that the the electron mobility is limited by impurity scattering with a slight lattice scattering component for doped coatings, while the low mobility observed in undoped coatings is due to grain-boundary scattering. The diffraction measurements show a strong preferential orientation which is independent of the doping level. Electron probe microanalysis shows that it is a plausible assumption that the fluorine occupies the oxygen positions in the lattice, while the free electron density is about one third of the fluorine concentration.