Magnetic phase transition temperature of the PbFe Nb O (PFN) nanofilm on the SrTiO substrate was reported to be about 50 K higher than that in the bulk samples. We carried out comparative Raman studies of a 90 nm-thick PFN epitaxial film on SrRuO -buffered (001) SrTiO substrate and the bulk samples of ceramic PFN and a single crystal. It was found out that the bands at ≈250 cm and ≈700 cm in the spectrum of the film, corresponding to Fe[sbnd]O vibrational modes, are shifted by about 20 cm to higher frequencies as compared to the bulk samples. This result is in line with the predictions of the recent first-principles calculations that compressive misfit strain stimulates the disorder in the Fe and Nb distribution in the lattice, leading to an increase of the magnetic phase transition temperature. Such disordering might cause the changes in the Fe-sublattice of PFN seen in the Raman spectrum.