To find the percolation threshold for the electrical resistivity of metallic Ag-nanoparticle/titania composite thin films, Ag-NP/titania composite thin films, with different volumetric fractions of silver (0.26 a parts per thousand currency sign phi(Ag) a parts per thousand currency sign 0.68) to titania, were fabricated on a quartz glass substrate at 600 A degrees C using the molecular precursor method. Respective precursor solutions for Ag-nanoparticles and titania were prepared from Ag salt and a titanium complex. The resistivity of the films was of the order of 10(-2) to 10(-5) a"broken vertical bar cm with film thicknesses in the range 100-260 nm. The percolation threshold was identified at a phi(Ag) value of 0.30. The lowest electrical resistivity of 10(-5) a"broken vertical bar cm at 25 A degrees C was recorded for the composite with the Ag fraction, phi(Ag), of 0.55. X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and transmission electron microscopic (TEM) evaluation of the effect of the morphology and the nanostructures of the Ag nanoparticles in the composite thin films on the electrical resistivity of the film revealed that the films consist of rutile, anatase, and metallic Ag nanoparticles homogeneously distributed in the titania matrix. It could be deduced that the electrical resistivity of the thin films formed at 600 A degrees C was unaffected by the anatase/rutile content within the thin film, whereas the shape, size, and separation distance of the Ag nanoparticles strongly influenced the electrical resistivity of the Ag-nanoparticle/titania composite thin films.