Aim: The present study assessed the prevalence of child exposure to environmental tobacco smoke (ETS) among families with smoking members. Methods: Secondary analysis was conducted on data from a survey done in Jodhpur district (Rajasthan) on substance use in 11459 households. Frequency of smoking by residents in households with children below 10 years of age was ascertained. Results: About 24.5% of children were exposed to ETS. Among surveyed households about 40% had at least one tobacco user and 22.9% at least one smoker. About 86.9% of smokers reported dependent use of tobacco. Among smoking households, 82.7% had at least one child below 10 years of age. Almost all (99.3%) of these households reported daily smoking by members and 55.4% the use of more than 20 cigarettes per day. Conclusions: Tobacco users should be advised about how to limit children's ETS exposure and policy formulation on tobacco control programmes should take this aspect of tobacco use into account. (Contains 1 table.)