Air pollution is increasing in urban areas of Nepal, and the major source of this problem is transport sector. Number of vehicles increases at the rate of over 10 percent per year. Nepal distributes unleaded petroleum all over the country but there are records of adulterated fuel supply by dealers thus making the condition worst. Nepal has set vehicular emission standards of CO, HC and smoke. In general 23% vehicles emitted more than the standard fixed. Maintenance of vehicles and monitoring systems are relatively unsatisfactory, asking to aware people about traffic norms, maintenance of vehicles and quality of fuel. An inspection on road and air quality monitoring programmes should be launched by the government.