Amorphous thin films of Se80-xTe20Pbx (0 < x < 2) have been prepared by a thermal evaporation technique. Dark and photoconductivity of the samples was measured at different temperatures. The value of the DC activation energy DeltaE(a) and the optical band gap E-g(opt) for Se80Te20 was found to be similar to 0.67 and similar to 1.68 eV, respectively. The addition of a small amount of Pb (0.6 at.%) to the Se-Te system decreases DeltaE(a) ( similar to 0.3 eV) and E-g(opt) ( similar to 1.39 eV) considerably. However, further addition of Pb (up to 2 at.%) does not cause much change in these parameters. The photoconductivity is found to increase with increasing temperature and light intensity. The square-root dependence of photocurrent on the illumination intensity indicates that the recombination process is bimolecular. The photosensitivity and the differential lifetime are also reported for Se80-xTe20Pbx (0 < x < 2) thin films.