BackgroundAdvance directives (ADs) were implemented in Portugal in 2012. Although more than a decade has passed since Law 25/2012 came into force, Portuguese people have very low levels of adherence. In this context, this study aimed to identify and analyse the attitudes of people aged 18 or older living in Portugal towards ADs and to determine the relationships between sociodemographic variables (gender/marital status/religion/level of education/residence/whether they were a health professional/whether they had already drawn up a living will) and people’s attitudes (...) towards ADs.MethodsAn online cross-sectional analytical study was conducted using a convenience sample. For this purpose, a request (email) that publicized the link to a –form—which included sociodemographic data and the General Public Attitudes Toward Advance Care Directives (GPATACD) scale—was sent to 28 higher education institutions and 30 senior universities, covering all of mainland Portugal and the islands (Azores and Madeira). The data were collected between January and February 2023.ResultsA total of 950 adults from completed the online form. The lower scores (mean 1 and 2) obtained in most responses by applying the GPATACD scale show that the sample of the Portuguese population has a very positive attitude towards ADs. The data showed that women, agnostics/atheists, health professionals and those who had already made a living will had more positive attitudes (p < 0.001) towards ADs. There were no statistically significant differences in the attitudes of the Portuguese population sample towards ADs in relation to marital status, education level, and residence.ConclusionThe results obtained enable us to confirm that this sample of the Portuguese population has a positive attitude towards ADs. We verify that there are certain fringes of this sample with certain sociodemographic characteristics (women, agnostics/atheists, health professionals and those who had already made a living will) that have a more positive attitude towards ADs. This data could facilitate the implementation and adjustment of relevant measures, particularly in the field of health education and aimed at groups with less favourable attitudes, to increase the effectiveness of voluntary exercise of citizens’ autonomy in end-of-life care planning. (shrink)