Lead silicate glassy and composite films were deposited on different substrates by reactive r.f. magnetron sputtering. Three different plasma compositions were used (pure Ar, Ar 5%O2 and Ar20%H-2) in order to study both the compositional changes and the electrical behaviour of the deposited films. X-ray diffraction analysis showed the presence of small Pb crystallites embedded in the silicate matrix of the films. The crystallite dimensions increased with increasing film thickness until it reached a steady value. The stoichiometry of the films was determined using Rutherford backscattering analysis, whereas the electrical properties were studied by measuring the sheet resistance of the films as a function of the temperature in the range 80 300 K. The correlation between the stoichiometry, microstructure and electrical sheet resistance is discussed.