©2014 Elsevier Ireland Ltd. All rights reserved. ; OBJECTIVE: We aimed to culturally adapt and validate METER in the Portuguese population, and to define cut-off values for adequate health literacy. METHODS: We used the standard procedure for the adaptation of the words and surveyed health professionals to select the non-words. The instrument was administered to a total sample of 249 participants and retested in a sub-sample of 45 after three months. Cut-offs were defined using the modified Angoff procedure. Construct validity was assessed through association with educational attainment and health-related occupation. RESULTS: Exploratory factor analysis revealed two dimensions of the instrument, one for words and another for non-words. METER showed a high degree of internal consistency, and acceptable test-retest reliability. Adequate health literacy was defined as scoring at least 35/40 in words and 18/30 in non-words. Physicians scored higher than any other group, followed by health researchers, researchers from other areas and by people with progressively lower levels of education (p