Deteriorating air quality is peril to human health in urban areas. Vehicular traffic is the major contributor to air pollution in cities. Street trees, being nearest to the source, can effectively reduce pollutants from ambient air. Pollution tolerant species can be more effective in this process with minimal physiological damage to their system. Pollution tolerance of the abundant street tree species in Ludhiana was studied and most of them were found to have intermediate tolerance. 17.27 per cent of the trees were tolerant and 20.4 per cent were sensitive. The most abundant species, Alstonia scholaris was sensitive to air pollution and can be used as indicator. More number of pollution tolerant species should be planted in industrial and commercial areas which have higher pollution load.