AbstractA method is described which allows to include complete multicomponent formulation of diffusion and heat conduction in the solution of the time‐dependent conservation equations of a laminar flat flame. Calculations with simplified transport models are presented for comparison. — For the ozone decomposition flame this method is used for the determination of the flame velocity of freely propagating flames as a function of the initial ozone oxygen ratio. There is agreement with experimental values. Discrepancies between calculated results given in the literature and those of experiments are explained.