The International Workshop on Web Personalization and Recommender Systems is organized by Xiaohui (Daniel) Tao, Xujuan (Susan) Zhou, Sheng-Tang Wu, and Luke Liming Chen. Web personalization and recommender systems are two important technologies that have been developed to cope with the severe problem of informationoverload on the Web. Web personalization systems serve users with consideration of user personal interests and preferences; recommender systems suggest Web users’ information and products to align with their personal demands. For many years, many groups have invested a great deal of effort in these areas and have made significant achievements. However, challenging problems remain that limit the full exploitation of personalization and resource selection through recommendation, both from the technology perspective and from the human and social perspective. Targeting these interesting and challenging questions, the WebPRES 2010 workshop aims at seeking a breakthrough on the existing problems in Web personalization and recommender systems, exploring an innovative route that smartly marries the techniques of Web personalization to those of recommender systems. The WebPRES 2010 workshop provides a forum for researchers and practitioners from different countries and regions and strengthens their research on Web personalization and recommender systems.