Laser-activated oxidation of thin metal films by the action of pulsed laser radiation is investigated theoretically and experimentally. A physical and mathematical model based on the Cabrera-Mott oxidation theory is developed. The basic relations, describing the process, are obtained numerically. Four different experimental methods have been used to examine qualitatively and quantitatively the laser-activated oxidation. The results obtained show that pulsed laser irradiation of thin metal films in the oxidizing environment may cause buildup of the thin oxide layer, which is very stable and may be used as a masking layer in the laser lithography. Comparison between experimental and theoretical results shows that the developed theoretical model describes the oxidation process well, and it may be used to find the optimum conditions for the thermochemical laser treatment of thin metal films.