Cytogenetic monitoring provides information on both the health status of the population under study and the impact of genotoxic factors, i.e., the cytogenetic status of a person can serve as a biomarker of the level of exposure to genotoxicants, including various types of smoking. Purpose - to investigate the effect of different types of smoking on the cytogenetic status, namely, to analyse the cariological parameters of buccal epithelial cells of the oral mucosa in teenagers and young adults. Materials and methods. The cytogenetic status was studied by analysing the karyological parameters of buccal epithelial cells of the oral mucosa in 114 adolescents aged 15 to 24 years, who were divided into groups: the Group I included 26 people who smoke traditional cigarettes; the Group II - 22 people who smoke electronic cigarettes (vapes); the Group III - 23 people who smoke tobacco heating devices (IQOS); the Group IV - 43 people without smoking habits. Results. A significant increase in epithelial cells of buccal epithelium with nuclear disorders was found in smokers compared to the group of people without smoking habits. In addition, in individuals without smoking habits, no nuclear disorders such as protrusions, proliferation rates, early stage of nucleus destruction and completion of nucleus destruction were detected. Conclusions. The sensitivity of buccal epithelial cells to the effects of different types of smoking was established, which affects changes in cariological parameters. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the author.