 The mini-emulsion technique is a particular case in the family of heterophase polymerizations, which allows the formation of functionalized polymers by polymerization or modification of polymers in stable nanodroplets. We present here an overview of the different polymer syntheses within the mini-emulsion droplets as reported in the literature and of the current trends in the field. This article was authored by Daniel Crespi and Catarina Landfester.