Uncontrolled urbanization and industrial development had put pressure on the air quality through the industrial emission and vehicular movements in Indian cities. Rain water is considered to be the purest form of water and it is being contaminated through anthropogenic source of emission. The present investigation is carried out to assess the air quality through rain events that occurred in Puducherry from October 2014 to January 2015. The rain water samples were collected from selected residential, commercial, industrial and rural areas to account the effects of air pollution. The rain water samples were analyzed for electro-conductivity, total dissolved solids, acidity, alkalinity, hardness, sulphate and chloride as per the standard methods(APHA,2005).On comparing the industrial, residential, commercial and rural area, the study had shown statistically significant difference (ANOVA, P<0.05) in total dissolved solids, chloride, carbon di-oxide, acidity and sulphate in rain water. The composition of the rain water differs from place to place due to interferences of local source of air contaminants. Thus the effect of air pollution can be assessed from the physico-chemical characterization of rainwater samples. There was higher concentration in the first rain of the season, after which the concentration decrease. This is due to wash out of the air pollutants in the subsequent rain. The lower concentration of parameters in water samples still indicates the contamination due to air pollution.