Short-term measurements of PM10, trace gases (SO2, NO2, and O-3) and heavy metals during Diwali festival were studied in a moderately polluted site in the city of Jamshedpur (India). In this study, Diwali day event recorded extremely high 12-h PM10 levels (500.5 mu gm(-3), which is > 5 times to the WHO standard) and massive loadings of ozone (53.33 mu gm(-3)), SO2(8.6 mu gm(-3)) and NO2 (73.32 mu gm(-3)), On Diwali day, all the measured values for PM10, SO2, NO2 and O-3 were found to be higher than prescribed limit of National Ambient Air Quality Standard (NAAQS) (PM10 = 60 mu g/m(3)). The first time study about any firework episode was carried in this region. The concentrations of Fe, Zn, Pb, Mn, Cu, Cd, Be and Ni were higher by the 2.2,1.5,2.8,1.6,2.2,1.2,5.9 and 3.3, times respectively, on Diwali as compared to normal days values. The metal concentrations on Diwali day were found to be significantly different from a normal day (except Zn & Cd). In Diwali day the Diurnal variation of PM10, SO2, and NO2 was found to be significantly higher than daytime concentrations for a normal day (control). It was estimated that firework aerosol contributed 21-27% to ambient PM10 on Diwali. Inter correlation among the trace gases, PM10 and metals are clearly indicates the fireworks emissions extremely fluctuates in air quality. These results indicate that fireworks episode during Diwali festival affected the ambient air quality adversely due to emission and accumulation of PM10, SO2, NO2, O-3, and trace metals.