Objectives: The aim of this paper is to demonstrate the possibility of determining biomarkers of passive smoking in adults through the analysis of urine samples. Material and methods: The material used for analysis is urine. The procedures for determining nicotine and its metabolites in urine using mass spectrometry, as well as gas and liquid chromatography methods, are described. Results: The results of various studies conducted on individuals who smoke or are exposed to passive smoking are being compared. The average cotinine level in the urine of non-smokers exposed to passive smoking was 56.544 ng/mL for women and 65.234 ng/mL for men, while the average 3-OHK level in the urine after exposure was 41.501 ng/mL for women and 14.941 ng/mL for men. Conclusion: Exposure to passive smoking can be reliably measured by analyzing nicotine and its metabolites in urine. Establishing a good threshold value is crucial due to differences in nicotine metabolism. Monitoring exposure is essential due to the development of diseases associated with passive smoking.