Recently, altmetrics have emerged as alternative means of measuring scholarly impact, aiming at improving and complementing both traditional and web-based metrics. The aim of the present study is to contribute to the altmetrics literature by providing an overview of the coverage of altmetrics sources for the Aristotle University of Thessaloniki (AUTh) publications. We used Scopus to collect all research articles stating AUTh as the affiliation of at least one author and published from 2010 to 2016. The altmetric data originated from Altmetric Explorer, a service provided by Only 17% of all publications retrieved from Scopus had some kind of mentions, while there was a clear increasing trend over the years. The presence of altmetrics was different from each attention source. Around 81% of all mentions came from Twitter. Facebook was a distant second, followed by news outlets. All other sources had very low or negligible coverage. The overwhelming majority of tweets had been posted by members of the public, who do not link to scholarly literature. Medical Sciences had by far the highest number of publications with altmetric scores, followed, in a distance by Sciences. However, Arts, Humanities and Social Sciences publications exhibited a significant altmetric activity. More research is needed in order to get a better insight into the altmetric landscape in Greece and develop an understanding about the kind of influence altmetrics measure, and the relationship, if any, between altmetric indicators and scientific impact.