Background. In our country and around the world at the moment there is no single method and approach for assessing the dental literacy of the population. Thus, the creation of a specialized methodology is the most optimal and reliable way to assess the literacy in the field of dental health and oral care of the population. The purpose of the study is to establish and study the level of dental literacy of patients with periodontal diseases. Methods. To establish and study the level of dental literacy of patients with periodontal disease, a comprehensive author's methodology was developed, which included a clinical dental examination, as well as self-assessment of oral health and risk factors affecting it. The stages of the methodology included anonymous questioning of patients using a specially designed questionnaire, assessment of the state of hard tissues of teeth and periodontal tissues through a clinical examination, and integration of the results of the examination and questioning for each respondent into a single database for further statistical processing. Results. According to our scale for assessing the level of dental literacy, the overall literacy of patients was at a low level and amounted to 7.51±0.04. When calculating the correlation dependence of the values of the severity of periodontal diseases and the dental literacy of the respondents, in general, an inverse linear correlation was found. The value of the CPI index component - periodontal pocket 4-5 mm showed a strong inverse correlation. The indicators of the correlation dependence of the level of intensity of caries in permanent teeth and the dental literacy of the respondents allow us to judge the presence of a strong inverse linear relationship with a value of - 0.862 (p = 0.021). Conclusion. A statistically significant conclusion was made about the presence of a relationship between the increase in the severity of periodontal diseases, the level of intensity of caries in permanent teeth and the deterioration in the patient's dental literacy, which allows using the proposed author's method to determine the level of dental literacy. Based on the proposed methodology, a program was developed to determine the level of dental literacy of the patient and targeted recommendations for each patient, taking into account individual factors that negatively affect dental health, as a result of which a certificate of registration of the computer program No. 2021668659 was received, registered in the Register of computer programs on November 18 2021.