Laser-induced photodissociation of ozone molecules is studied by irradiating isotope-mixed ozone gas with a narrow-band laser beam of around 1 mu m wavelength. Significant decomposition is detected only for the irradiated ozone isotopologue with the decomposition amount nearly proportional to the laser power. This result indicates that the process is not due to multi-photon absorption, but rather due to single-photon absorption through the rotationally resolved transitions in the (3)A(2 <-) (1)A(1) (v(2) = 1-0) band. (C) 2008 Published by Elsevier B.V.