The effect of pulsed nanosecond radiation from a frequency doubled Nd:YAG laser on several porphyrins in three solvents (chloroform, benzene, methanol) has been studied. For all three porphyrins (PPM, HPM, TPP), only irradiation in CHCl3 solutions can bring about the appearance of new spectra and the disappearance of original ones, but never in benzene or methanol solutions. The resulting products have been identified as the corresponding protonated porphyrins. We assume that the dielectric breakdown of chloroform most probably accounts for the reaction pathway.