This article presents the results of a study developed within the scope of the Project Health Literacy: a challenge in and for the elderly, funded by the Calouste Gulbenkian Foundation. It tried to evaluate the metric qualities of the Newest Vital Sign Test (NVS, Copyright © Pfizer Inc.) applied to elderly; evaluate the degree of health literacy of a sample of elderly Portuguese people; get to know the association between the degree of health literacy and some sociodemographic features, the general health state, and quality of life. It was conducted a quantitative study with 433 adults over 65 years of age, mostly female, and with heterogeneous levels of education. The instrument used was a battery of tests in order to assess the degree of health literacy (Newest Vital Sign), and the quality of life (WHOQOL). The NVS proved to be a reliable and sensitive to changes due to various demographic characteristics instrument. The results indicate that the majority of the participants (80%) showed a level of low health literacy, meaning that only 20% of respondents will be able to interpret and use effectively information related with health. Gender, educational attainment, age and marital status, as well as the perception of the elderly on their general health state and quality of life, proved to be variables that affect significantly the level of health literacy of participants. These results point to the urgent need to enhance health literacy in the elderly population, in general, and among the most vulnerable groups, in particular.