Nowadays, stringent environmental regulations have defined the sulphur content in diesel fuel to less than 10 ppm and further reductions are planned so it is important to develop an efficient desulfurization process like the process of oxidative desulfurization with ionic liquids. The goal of this work was to explore the process of oxidative desulfurization of diesel with ionic liquids. Desulfurization, the process of removing sulfur from diesel is carried out in the industry mainly by the hidrodesulfurization process but there are also other processes like biodesulfurization, oxidative desulfurization and adsorption desulfurization. Oxidative desulfurization with ionic liquids is a process that was developed in last decade and represents a revolutionary discovery for the industry because it has many advantages over the classic method. From a variety of experimental researches it can be discerned that significant efficiency in sulfur removal from diesel can be obtain with the combination of ionic liquids and suitable oxidative substance. Furthermore, significant efficiency of the process with ionic liquids is achieved if they are not miscible with water and don’t have pronounced polarity Second generation ionic liquids are the most represented in research because of their chemical and thermal stability. The most comprehensive studies of the process of oxidative desulfurization with ionic liquids were carried out with N-alkyl-pyridinium-based ionic liquids and imidazolium-based ionic liquids furthermore, using the amide-based ionic liquids an almost complete removal of benzothiophene and dibenzothiophene is achieved. The process of oxidative desulfurization with ionic liquids is preferably carried out at moderate temperatures, optimally at 70 °C during 180 minutes which is the optimum time of the process and with the ratio of ionic liquid and oxidant 1: 1.1.