The current state of vehicle technology development has been characterized by the production of a very wide range of different types and categories of vehicles. Modern vehicles are characterized by a great complexity of fitted parts and mechanisms. These facts inevitably lead to the intensive development of legislation that cover the entire field of the automotive industry, as well as its harmonization at the international level. From the very beginning of harmonization, Yugoslavia has played a very active role in the development and implementation of the Regulations adopted within the United Nations, the Economic Commission for Europe. As the legal successor, Serbia continued on that path, but due to the situation in the previous 30 years, the activities within the harmonization of regulations have been significantly slowed down, primarily with the European legislation. The paper presents the current state of harmonization of regulations in Serbia with European legislation, as well as certain inconsistencies that occurred during the application of national regulations and performed comparative analysis. Also, an overview of the plan for harmonization of legislation has been given, and some examples of noncompliance are pointed out, which should be overcome with the proposed harmonization plan.