In the past 15 years, high transfer efficiency together with a high degree of automation and high environmental acceptability, combined with excellent film properties, have made cathodic electrodeposition (CED) of paint the most important priming method in car manufacturing. In the introductory part, these different aspects will be highlighted and the history of priming car bodies will be explained with special emphasis being laid on the different stages of cathodic EC development. The different paint layers normally applied to car bodies will also be introduced and discussed. The main part of the paper explains the fundamentals of the chemistry of cathodic deposition of paint and the principles of the application process. The current status of cathodic electrodeposition will be examined with respect to application, film properties, film curing behaviour and also taking into account some engineering details. Finally, the current research and development activities as well as future developments will be presented.