The smoking pandemic is a global public health and economic problem. Passive smoking has a detrimental effect on the health of other people indirectly exposed to tobacco smoke. Therefore, innocent passive smokers in their vicinity are at risk of becoming ill with all the smoking diseases and consequences. The biggest victims, however, are children who are exposed to tobacco smoke, or rather victims of secondhand smoke, because they cannot choose to breathe air primarily in the family and then in the environment. The aim of this study is to determine the association of parents' smoking habits with nicotine values in the child's body. In order to collect data, I conducted a suitable survey that I conducted at the Srebrnjak Children's Hospital per 100 subjects, and in parallel with hospitalized children, conducted a Kotina test on 100 subjects, which objectively determined the exposure of children to nicotine in secondhand smoke. The subjects were hospitalized children and their parents, and I statistically analyzed the data and identified possible differences with respect to gender, age and educational level of parents, social status, and the significance of the association of higher nicotine values in the child's body with their parents' smoking habits (one or both) The results of the study show that the place of residence is generally dominated by the urban population, and it is also evident that a higher proportion of children with a negative cotinine test are in the urban environment (75.38%), while in rural areas a higher proportion of children is exposed to tobacco smoke (51.43%), in our sample with statistical significance (p = 0.015). With regard to marital status, there were also statistically significant differences where the cotinine test was significantly more often positive in children whose parents were divorced. The study found a tendency that the percentage of parents with a university degree is predominantly less exposed to cigarette smoke, and statistical significance was found in the children of parents with a lower level of education (p = 0.041), which proves that the children of parents with a lower level of education were more exposed to tobacco smoke. Similarly, according to the survey data, poor material status significantly influences smoking habits (p = 0.039), that is, parents of lower material status smoke more. In parents who smoke in the presence of children (88% and 87%), whether indoors or outdoors, according to the data, there was no statistical significance with respect to the results of the cotinine test. Number of cigarettes smoked, number of smoking years, or concern for adverse effects on children the health of oneself or children do not have a statistically significant difference according to the cotinine test result (p = 0.693, p = 0.336, p = 0.812, p = 0.748), but the fact is that if the partner of the study person tried to quit smoking there is a statistically significant difference in the sense that the cotinine test was less positive in children, henceless exposure of children to tobacco smoke (p = 0.009). The study showed that there was no statistical significance between parents' smoking habits and the results of the cotinine test.