Continuous crystallization methods are reported in this review, with a particular focus on microfluidic systems. Advances in the nonmicrofluidic crystallization systems include multistage crystallization and intensifying the mixing of plug flow devices and generally improve the product quality and yield but do not resolve the scaleup issues. Microfluidic systems lead to an extremely reproducible particle production with numbering-up possibilities for large-scale applications. An overview of microfluidic devices is reported, focusing on the points of improvement and the challenges that still remain.