The motor vehicles are the main source of atmospheric pollution, especially carbon monoxide, hydrocarbons and nitrogen oxides (NOx). To reduce these emissions for environmentally acceptable levels, Europe and the United States have developed control programs, where are set emissions limits for new vehicles, which are gradually reduced over time and the compliance must be done through standardized tests in laboratories. However, Europe is facing a problem: NOx level in the cities is not being reduced in the same proportion of the homologation limits, due to two factors: the poor representativeness of the test procedures in comparison of the “real world” and the use of engine management software that produces low pollutants just in laboratory tests. Several studies about real world emissions have pointed to vehicles, approved in the laboratory, emitting in the streets about 7 up to 40 times more NOx than the homologation limit. To fix this problem, since September/2017 Europe will add to the vehicles type-approval process a real driving emissions test (Real Driving Emissions - RDE), where the vehicle must meet the limits when running in streets coupled to a portable measuring system. In order for the RDE procedure be applied effectively to the Brazilian reality, it is necessary to discuss three relevant points: the differences between the national and the European fleet, the procedure itself, focused on NOx control and the specific characteristics of Brazilian cities. This paper has the objective to discuss about RDE principles and how it can to be applied in the Brazilian reality.