One of the most important polymers for membranes manufacturing is Polysulfone because of its remarkable properties, like chemical stability, mechanical and thermal properties, and also due to the possibility to obtain a wide range of polymeric membranes for different applications. Membrane functionalization is a key process to obtain high-value membrane materials. The present review paper is a guide related to the latest researches performed in the field of functionalization reactions of polysulfone membranes. It is based on both approaches – reactions performed at the surface of the membranes and also on applications. In this article, ion exchange membranes, biomedical or catalyst applications are presented and commented. Furthermore, key factors or analysis related to the main properties of functionalized membranes are also considered. © 2020 Elsevier Ltd