PIP: A survey was conducted by the National Family Health Survey (NFHS) in India among 88, 562 households in 1992-93 to examine the link between the use of biomass fuel in cooking and the increased risk of tuberculosis (TB) in India. Cooking smoke that contains many noxious components compromises the pulmonary immune system that triggers the development of active TB. It could also facilitate the spread of infection by bringing about coughing. This analysis shows the high prevalence of active TB (51% of active TB among persons age 20 years and older) with the household's use of a biomass cooking fuel. The effect remains statistically significant even after adjusting for the effects of other demographic and socioeconomic variables. Women, particularly those living in rural areas, were more likely affected by tuberculosis. The cases of active TB may however be underreported in the NFHS because of the stigma attached to the disease. These findings suggest that TB prevalence could be reduced significantly in India, and perhaps in other developing countries, by lowering exposure to cooking smoke from biomass fuels.