Introduction: Street vendors are the most dominant occupation in urban and rural areas. Street vendors are exposed to several environmental pollution. They inhale toxic compounds such as carbon monoxide, carbon dioxide, ozone, nitrogen dioxide and other volatile organic chemicals. This is due to emission from vehicles and traffic. The aim of the study is to assess lung function on street vendors of the Chennai region.
 Materials and Methods: The study is done among street vendors in chennai region. The study included 50 people where 25 people are from the exposed group and 25 people are from the normal group. It was conducted by using a computerised spirometer. The total air capacity of the lung. The data was collected and entered in SPSS software. The results were obtained by doing an independent sample T test.
 Result and Discussion: Parameters like FVC, FEV1, PEF, FEV1/FVC were used to assess the lung function. It was observed that there is a decline in pulmonary functions parameters of the street vendors and it was not statistically significant .
 Conclusion: Thus the effect of pollution by the vehicles may be responsible for the pulmonary function impairment on street vendors affecting their lungs and other organs. This can be prevented by using face masks, lifestyle modification etc.