In the past decades, ionic liquids (IL) evolved from a “designer solvent” to a well-known and well-characterized class of compounds useful in reactions, extractions, and other applications. By an increasing number of synthesized ILs also new fields of application were uncovered. The todayʼs research interest covers a range for direct use of ILs, application as embedding material or as catalyst. In this brief review, we present diverse applications of pure native ILs as well as these of polymerized ionic liquids (PILs). These charged polymers unite the presented advantages of both, ionic liquids and solid polymer structures. We also show the recent developments in the areas of drug delivery, catalysis and catalyst immobilization where these particular compositions demonstrate improvements compared to existing solutions. Besides the advantages, we likewise discuss some limitations and drawbacks. •An overview of ionic liquids and polymerized ionic liquids, their properties and characteristics is given•Recent developments of applications in catalysis, separation processes and drug delivery are presented