The results of the photodissociation of chlorinated methane's: CH4, CH2Cl2, CHCl3, and CCl4, at 355 nm and intensities up to 1010 W·cm−2, are presented. The absorption of two- to five-photons is responsible for the molecule to reach different dissociative electronic states. From the dissociation products the effect of chlorine isotopes, 35Cl and 37Cl, was observed, mainly in the formation of: Cl+, HCl+, CCl+, and CHCl+, and CCl2+.