Microflow technology, i.e., the use of micro fluidic devices for continuous flow synthesis, represents a highly useful and increasingly popular method in organic chemistry. Recently, also an increasing number of polymer synthesis protocols attain benefit from this technique. In particular, the control of highly exothermic, fast polymerization reactions can be improved due to the excellent heat and mass transfer within the small dimensions of the microreactors. Continuous flow setups with different micromixer geometries and flow patterns are currently used for the preparation of a variety of macromolecular architectures by ionic and (controlled) radical polymerization techniques. This Perspectives reviews recent developments in synthetic strategies and reactor design for the homogeneous synthesis of polymers in microflow systems and emphasizes future challenges and promise for applications. Polymer synthesis by radical, anionic, cationic, and coordinative polymerization is considered as well as different polymer topologies generated (linear, branched, and dendritic architectures).