Objective: to investigate the psychometric properties of the Brazilian Portuguese version of the health literacy questionnaire European Health Literacy Survey Questionnaire short-short form (HLS-EU-Q6) in Brazilian adults. Method: the instrument was translated and pre-tested in a sample of 50 individuals. Subsequently, it was applied to a sample of 783 adult individuals. The data went through an appropriate process of testing the properties, with the combination of techniques of Exploratory Factor Analysis, Confirmatory Factor Analysis and Item Response Theory. For the assessment of reliability, the Cronbach's alpha and McDonald's Omega indicators were used. Cross-validation with full data analysis was applied. Results: the majority of the participants was female (68.1%), with a mean age of 38.6 (sd=14.5) years old and 33.5% studied up to elementary school. The results indicated a unidimensional model with an explained variance of 71.23%, adequate factor load levels, commonality and item discrimination, as well as stability and replicability of the instrument to other populations. Conclusion: the Brazilian version of HLS-EU-Q6 indicated that the instrument is suitable for indiscriminate application in the population to which it is intended to assess health literacy levels.