The possible role of photoinduced electron transfer is investigated in the fluorescence quenching of thedonors metallo octaethylporphyrins (zinc octaethylporphyrin and magnesium octaethylporphyrin) inpresence of the acceptor 2-nitrofluorene in polar acetonitrile liquid medium by using steady state andtime-resolved techniques at the ambient temperature (300 K). The donors are selectively excited at the Qband (S₁state), where 2-nitrofluorene has negligible absorbance. The observed bimolecular fluorescencequenching rate constants for the present donor–acceptor systems from steady state as well as time-resolved fluorescence quenching data are of the order of 10¹⁰ L/(mol s) (less than the diffusion-controlledlimit of 1.9 × 10¹⁰ L/(mol s)). The moderately negative values of Gibbs free energy change (ΔG°) indi-cate that photoinduced electron transfer from the metallo-porphyrins to 2-nitrofluorene in acetonitrilesolvent is possible upon photoexcitation of the former molecules. Moreover, the fluorescence quench-ing rates for both the donor–acceptor systems obtained from Marcus theory agree quite well with theobserved values from fluorescence quenching measurements (especially time-resolved measurements).