This article reviews microwave-assisted heterogeneous gas-phase catalysis. To date, this special means of non-classical energy input by microwave radiation is still a fringe area of catalysis research, and alternative reaction engineering in chemistry and chemical engineering. However, microwave-assisted heterogeneous gas-phase catalysis is expected to gain significant popularity in academia and industry in the near future. Experimental set-ups that have been described in literature are critically reviewed, and concepts for the design of improved experimental set-ups are provided in this article. Historical developments, current tendencies, and a short introduction to the theory of dielectric heating are discussed.