Air is the primary prerequisite for life on the earth. Due to the rapid increase in industrial and automobile emissions, its quality is worsening day by day. The accumulation of air pollutants on the leaves of plants growing along the roadside causes harmful changes in their biochemical parameters. The present investigation deals with the effects of air pollutants on the total chlorophyll and ascorbic acid contents of commonly available medicinal plants in the study area during different seasons. The plants selected for the study were Azadirachta indica, Cassia fistula, Ricinus communis, Terminalia arjuna, and Vachellia nilotica. It was recorded that the maximum air pollutant level was in the winter season followed by summer and monsoon seasons. The total chlorophyll content decreased and the level of ascorbic acid increased with the increase of air pollutant level. Season-wise, total chlorophyll content was significantly different in all the study plants; also site-wise except for Cassia fistula. The ascorbic acid content was significantly different for Azadirachta indica and Cassia fistula both at site-wise and season-wise. On the flipside, it was non-significant for Ricinus communis and Terminalia arjuna both at site-wise and season-wise. For Vachellia nilotica, seasonwise ascorbic acid values were significantly different but site-wise non-significant.