This review paper focuses on the effects of microwave irradiation on heterogeneous gas phase catalytic reaction systems. Both experimental and modeling approaches are discussed. The currently available methods for temperature measurements in the microwave heating of solid particles are critically examined. The existence of microwave-created temperature gradients in beds of solid particles is discussed. The not fully established mechanism of catalyst (nano)particle heating and imperfect temperature measurement techniques implicate that different effects are often observed and contradictory conclusions are drawn. For further progress here, the development of accurate and possibly non-invasive techniques for local temperature measurements under microwave irradiation is needed.