This present article has the objective to show, through a search with the Controlar Enterprise, what is the efficiency of the vehicular inspection to improve the air quality in the city of Sao Paulo. This inspection became mandatory by the Municipal Law-Decree nr. 11.733, in March 27, 1995 and Municipal Law nr. 12.157, in 1996; the Municipal Decree nr. 50.232 in November 17, 2008; with Resolutions of the National Committee for the Natural Environment, as seen in the article 104 of the Brazilian Code of Traffic. Controlar is a enterprise with national bank stock to control and license of Sao Paulo City Administration to vehicular inspection. The present study is exploratory, with basic quality, composed by interviews. Those interviews were recorded, and then transcripted. The data were submitted to a Content Analysis according Bardin (2010), floating reading, codification and categorization. Starting with this categorization, the data were analyzed and interpreted. The data resulting revealed that the Vehicular Inspection had improve the air quality of Sao Paulo City; after the beginning of this process, there was a reduction of the emission of pollutant in the air, originated from vehicles in bad conditions of conservation. It is believed that with the mandatory of the adhesion of 100% of the fleet, the wished level of the air quality be reached. This new scenery has been shown favorable to the maintenance of the life quality for the future generations.