Abstract.As a consequence of recent experimental results, previously established systematics for prompt fission γ -ray spectra (PFGS) characteristics as function of both atomic and mass number of the compound system have been revised. Although based on purely empirical dependences, it allows estimating average gamma-ray multiplicity, mean and total photon energy in cases, where the target nuclei are either not available or not accessible experimentally. Based on this systematics, we show in this paper that PFGS characteristics may also be predicted for fission induced by fast neutrons. Our calculations were performed for the target nuclei 238 U, 235 U and 239 Pu in the neutron energy range from 0 to 20 MeV, and the results are compared to existing experimental and theoretical values.