Scientix, the community for science and maths education in Europe, supported by the EU within the 7th Framework Programme, was created to promote sharing and exchange of good teaching practice and learning materials in STEM education. The Scientix resource repository (http://www.scientix.eu/web/guest/resources) collects teaching materials from science education projects financed by the EU under the 6th and 7th Framework Programmes, the Lifelong Learning Programme and by other national and international initiatives. In the last 2 years of Scientix, the number of educational resources as well as their availability and distribution via the portal, has rapidly increased. Scientix repository has over 800 educational resources from STEM subjects available for teachers. The Scientix portal needs sustainable support for quality assurance for such a large quantities of resources. It has been clearly identified that user community-based solutions could be the key of quality assurance providing the much needed volume for the reviews [1]. In this paper we analyze how teachers as users of educational resources repositories perceive the quality as well as how does the resources meet teachers’ expectations. The evaluation and rating of educational resources in this matter has been done by teachers through a common tool, the social ranking. Teachers took into account a set of criteria for evaluation, including pedagogical value, curricular integration, clarity presentation, etc. Additionally, we look into the evaluation of learning resources carried out for the Scientix Resources Awards [2]. In this case, the criteria are set and teachers used them to determine the “best” resources published in the portal within a certain period.