Objective: To assess oral health literacy level and oral health information of Iranian adults in Tehran, and to determine the factors related to oral health literacy. Basic research design: A cross-sectional population study. Participants: A random sample of 1,031 adults in Tehran, Iran. Methods: Oral health literacy was measured using an oral health adult literacy questionnaire (OHL-AQ). Variation in use of information sources by socio-economic and demographic background was estimated by odds ratios. A multiple linear regression model served to determine predictor factors of OHL-AQ scores controlling for characteristics of the subjects and number of information sources. Results: The mean OHL-AQ score was 10.5 (sd 3.0). Women (p<0.001), younger (p<0.001), and better educated participants (p<0.001) had higher OHL-AQ scores. The most common sources of oral health information were dentists (52.6%), and TV/Radio (49.5%). According to the regression model, females (p=0.001), high educational level (p<0.001), and use of multiple information sources (two sources p=0.01, three sources or more p=0.002) were the main predictor factors of OHL-AQ scores. Conclusions: The average oral health literacy level of Iranian adults was low. Disseminating evidence-based oral health care information from multiple sources including TV/radio, dentists, and other health professionals in different settings should improve public oral health literacy. Keywords: oral health; oral health literacy; information sources; Iran