Microwave-assisted chemistry is about to change the art and practice of synthesis performed in many academic and industrial laboratories. One of the major drawbacks of this enabling technology is the difficulty associated with scale-up. Because of the limited penetration depth of microwaves into absorbing media, the solution to scale-up lies in continuous-flow processing. In this review we summarize the current state of the art in this field and present an overview on published examples of microwave-assisted synthesis using continuous-flow and stop-flow processing in custom-built or commercially available microwave reactors.