The ACM Recommender System conference is the premier international forum for the presentation of new research results, systems and techniques in the broad field of recommender systems. Recommendation is a particular form of information filtering, that exploits past behaviours and user similarities to generate a list of information items that is personally tailored to an end-user's preferences. The sixth conference in this series, RecSys 2012, will bring together researchers and practitioners from academia and industry to present the latest results and identify new trends and challenges in providing recommendation components in a range of innovative application contexts. As RecSys brings together the main international research groups working on recommender systems, along with many of the world's leading e-commerce companies, in the last number of years, it has become the most important annual conference for the presentation and discussion of recommender system research. In addition to the main technical track, RecSys 2012 program will feature keynote and invited talks, tutorials covering state-of-the-art in this domain, a workshop program, an industrial track and a doctoral symposium.