In this paper, different polymerization processes for the synthesis of polymers in homogeneous phase comprising some microsystems are reviewed. Due to their unique characteristics, microsystems allow rapid heat removal and mixing. This contributes to significantly improve the control over the polymerization by reducing or eliminating mass transfer limitations and hot spot formation. As a consequence macromolecules with better-controlled characteristics are obtained like specific molecular weights and narrower molecular weight distributions. Most common microsystems include microchannel-based and microtubular reactors used for heat-transfer sensitive reactions. Micromixers are also an important class of microsystems from which polymerization processes sensitive to mixing masking can benefit a lot. The typical few milliseconds mixing achieved in these micromixers and the easy operation at high temperatures (and pressures) allow for new operating process windows (e.g. high temperatures combined with short reaction times, higher reactant concentrations) and selective reaction pathways. Therefore, higher yields and selectivities can be obtained. Additionally, these microsystems are useful tools for high-throughput experiments (HTE) in order to generate libraries of (co)polymers and to rapidly assess different process parameters.