Background and aim: Children who are exposed to tobacco smoke (ETS) are at risk for a variety of health issues. There are enough legislative provisions in Indian law to safeguard children from ETS in outdoor settings, but no such specific rules exist to shield them from exposure indoors. This study aimed to examine the trend in under-five children's exposure to indoor tobacco smoke over the course of a decade (from 2005 to 2016) in India.Materials and methods: Data from the National Family and Health Survey (NFHS) for the years 2005-2006 (NFHS-3) and 2015-2016 (NFHS-4) on under-five children have been taken into consideration in cross-sectional analyses of the Demographic and Health Survey on India. Based on different sociodemographic factors, the propensity of indoor ETS among Indian children has been estimated and compared using both bivariate and multivariate logistic regression models.Results: The prevalence of indoor ETS among Indian children under the age of five has greatly risen over the past decade, rising from 4.12% to 52.70%. According to the findings, there has been a noticeable increase in every group of kids, regardless of their age, place of residence, geographic location, socioeconomic status, and literacy level of their mothers.Conclusion: In India, the incidence of indoor ETS among children under five has risen by 13 times in the last 10 years, endangering the country. As a result, the Indian government must prepare to take legislative action to safeguard children by passing laws that forbid smoking inside.