The International Conference on Information Processing and Management of - certainty in Knowledge-Based Systems, IPMU, is organized every two years with the aim of bringing together scientists working on methods for the management of uncertainty and aggregation of information in intelligent systems. Since 1986, this conference has been providing a forum for the exchange of ideas between th theoreticians and practitioners working in these areas and related fields. The 13 IPMU conference took place in Dortmund, Germany, June 28–July 2, 2010. This volume contains 79 papers selected through a rigorous reviewing process. The contributions reffect the richness of research on topics within the scope of the conference and represent several important developments, specifically focused on theoretical foundations and methods for information processing and management of uncertainty in knowledge-based systems. We were delighted that Melanie Mitchell (Portland State University, USA), Nihkil R. Pal (Indian Statistical Institute), Bernhard Sch¨ olkopf (Max Planck I- titute for Biological Cybernetics, Tubing ¨ en, Germany) and Wolfgang Wahlster (German Research Center for Artificial Intelligence, Saarbruc ¨ ken) accepted our invitations to present keynote lectures. Jim Bezdek received the Kamp´ede F´ eriet Award, granted every two years on the occasion of the IPMU conference, in view of his eminent research contributions to the handling of uncertainty in clustering, data analysis and pattern recognition.