In a process for heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, the starting reaction gas mixture is oxidized at a propene loading of <160 l (STP) of propene/l of fixed catalyst bedh over a fixed catalyst bed which is accommodated in two successive reaction zones A, B, the highest temperature of the reaction gas mixture within reaction zone A being above the temperature of the reaction gas mixture within reaction zone B.
