The catalytic performances of two multichannel microreactors and a lab-scale fixed-bed reactor have been compared in the oxidative dehydrogenation of propane (ODP) over VOx/Al2O3 as catalytic material. Under isothermal conditions both types of reactors showed approximately the same catalytic results (propane conversion and product selectivity). With increasing reaction temperature, however, axial temperature gradients appeared in the fixed bed reactor which led to differences in degrees of propane and oxygen conversion between the reactor types. The ODP reaction in the multichannel microreactor was described by a kinetic model. Computational fluid dynamics (CFD) simulations of a single channel using derived kinetics have shown that, in the stainless steel multichannel microreactor, only very small axial and cross-sectional temperature gradients (<1 K) occurred under all applied conditions. Furthermore, the simulations have shown that the thermal behaviour of the microchannels is strongly influenced by the heat conductivity and the thickness of the channel walls. Therefore, in order to achieve isothermal conditions, sufficiently thick walls with high heat conductivity have to be used. In contrast, thin walls and/or wall material with low heat conductivity should be used for an auto thermal operation or a coupling of an exo- and endothermic reaction.