This study undertaken in India was aimed at identifying the effects of the indoor air pollutants SO2, NO2 and total suspended particulate mater (SPM) generated from fuel used for cooking on respiratory allergy in children in Delhi. A total of 3,456 children were examined (59.2% male and 40.8% female). Among these, 31.2% of the children's families were using biomass fuels for cooking and 68.8% were using liquefied petroleum gas. Levels of indoor SO2, NO2 and SPM, measured using a Handy Air Sampler (Low Volume Sampler), were 4.60 +/- 5.66 microg/m3, 30.70 +/- 23.95 microg/m3 and 705 +/- 441.6 microg/m3, respectively. The mean level of indoor SO2 was significantly higher (p = 0.016) for families using biomass fuels (coal, wood, cow dung cakes and kerosene) for cooking as compared to families using LP gas. The mean level of indoor NO2 for families using biomass fuels for cooking was significantly higher in I.T.O. (p = 0.003) and Janakpuri (p = 0.007), while indoor SPM was significantly higher in Ashok Vihar (p = 0.039) and I.T.O. (p = 0.001), when compared to families using LP gas. Diagnoses of asthma, rhinitis and upper respiratory tract infection (URTI) were made in 7.7%, 26.1% and 22.1% of children, respectively. Respiratory allergies in children, which included asthma, rhinitis and URTI, could be associated with both types of fuels (liquefied petroleum gas [LPG] and biomass) used for cooking in the different study areas. This study suggests that biomass fuels increased the concentrations of indoor air pollutants that cause asthma, rhinitis and URTI in children. LP gas smoke was also associated with respiratory allergy.