Health literacy is an important predictor of health status, health behaviours, and other health outcomes. However, research on health literacy in the Arab world is scarce and no health literacy tool has been validated to test the health literacy level of the Lebanese population so far. The aim of this study was to validate Arabic translations of three commonly used health literacy assessment tools, the S-TOFHLA, the REALM-R, and the Brief Health Literacy Screening items. The tools were linguistically and culturally adapted to the Lebanese context, and 250 face-to-face interviews were conducted in an outpatient clinic in Beirut, Lebanon, between April and June 2015. The General Self-Efficacy Scale and socio-demographic questions such as gender, age, origin, education and chronic condition were included to assess predictive validity. Reliability of the instruments was found to be low to high (Cronbach's α =0 .94 for the S-TOFHLA, Cronbach's α = 0.46 for the REALM-R). Younger and highly educated participants scored higher on the S-TOFHLA. The Brief Health Literacy Screening items were significantly correlated with age, education, self-efficacy and the S-TOFHLA, reinforcing the convergent and predictive validity of the two tools. Results indicate that the S-TOFHLA and the three screening questions are a valuable tool to measure health literacy in Lebanon and, allowing for minimal adaptations according to each country's healthcare system, in the entire Arabic-speaking area.