Introduction and objective. A large number of colonies of Streptococcus mutans (SM) and Lactobacillus (LB) cariogenic bacteria in the saliva show a high risk of dental caries development. Cotinine is a biomarker of exposure to the tobacco smoke. The aim of the study was assessment of the number of Streptococcus mutans and Lactobacillus in the saliva of non-smokers and smokers considering the duration of smoking and the number of cigarettes smoked daily. The number of SM and LB was analysed in relation to the frequency of oral health check-ups. Materials and method. The investigated group comprised 124 people aged 20–54. 58 (46.8%) reported cigarette smoking; 66 (53.2%) reported they had never smoked cigarettes and had never attempted to smoke. Cotinine concentration in the saliva was assayed using the Cotinine test (Calbiotech), and the number of SM and LB with the use of the CRT bacteria test (Ivoclar Vivadent, Liechtenstein). Statistical analysis was conducted using Chi2 and Mann-Whitney tests. Test values of p<0.05 were considered statistically significant. Results. No essential correlation was stated between the number of SM and LB and the status of smoking, the number of cigarettes smoked daily and duration of cigarette smoking. Smokers who reported having dental check-ups at least once a year significantly more frequently had a small number of LB stated in relation to people who had dental check-ups to control their oral health less frequently than once a year. Conclusion. The number of SM and LB in saliva does not depend on the smoking status, the number of cigarettes smoked daily and duration of smoking.