Rate constants are obtained for vibrational relaxation from selected vibrational levels in S0 and S1 p-difluorobenzene (pDFB), induced by collisions with foreign gas, M. The levels studied are 52302 (∈vib = 2036 cm-1) in the S0 ground electronic state, and the pair of levels 31 (∈vib = 1251 cm-1), 31301 (∈vib = 1373 cm-1) in the S1 excited electronic state. The S0 level is explored by using stimulated emission pumping, single vibronic level fluorescence probing (SEP-SVLF), while S1 levels are studied by using the more conventional approach of monitoring the evolution of dispersed fluorescence as a function of added pressure of foreign gas. Collision efficiencies for relaxation of the S1 levels with M = Ar, CO2, C6H12 are in accord with expectations based on related studies of levels in S1 benzene. S0 p-difluorobenzene displays efficiencies for vibrational relaxation that are completely consistent with these S1 studies. We conclude that vibrational relaxation in polyatomics such as benzene and p-difluorobenzene should normally proceed with closely comparable efficiencies in both the excited and ground electronic states of the same molecule.