Objectives: This study aimed to investigate oral health-related knowledge in adults and to determine the effect of oral health knowledge on correct brushing and use of dental care products. Methods: The subjects of this study were 552 adults who visited dental clinic, and a self�administered questionnaire was administered. Statistical analysis was performed using the t-test, ANOVA, and multiple regression using the SPSS statistics program (ver. 23.0, IBM Co., Chicago, IL, USA). Results: The oral health knowledge level, correct brushing, and dental care product usage scores were found to be positively correlated (r=0.015, 0.016), and both correlation coefficients were statistically significant (p<0.05). Oral health knowledge was found to have a significant effect on correct brushing among oral health promotion behaviors (β=0.116, p=0.006), but it was not found to have a significant effect on the use of dental care products (β=0.053, p=0.214). Conclusions: Oral health promotion behavior is closely related to oral health knowledge, and it is thought that oral health promotion behavior can be improved by raising oral health knowledge levels.