The kinetics of the reaction of ozone with hydrogen sulfide was studied theoretically. High-level ab initio calculations were carried out to build the potential energy surface. The mechanism of the title reaction was found to be much more complicated than what is reported in the literature to date. According to our results, six different chemically activated intermediates are involved along the proposed mechanism on its lowest singlet potential energy surface that play an important role in the kinetics of this system. Multichannel RRKM-TST and CVT calculations have been carried out to compute the temperature dependence of the individual rate constants for different channels and also the overall rate constant for the consumption of the reactants. The major products are sulfur dioxide and water at lower temperatures, in good agreement with experimental reports, while at higher temperatures, formation of the other products like O2, H2SO, and radicals like cis/trans-HOSO, SH, HO3, and OH also become important.