Since their inception in 1979, the Linz Seminars on Fuzzy Set Theory have emphasized the development of mathematical aspects of fuzzy sets by bringing together researchers in fuzzy sets and established mathematicians whose work outside the fuzzy setting can provide directions for further research. The philosophy of the seminar has always been to keep it deliberately small and intimate so that informal critical discussions remain central. LINZ 2011 will be the 32nd seminar carrying on this tradition and is devoted to the theme “Decision Theory: Qualitative and Quantitative Approaches”. The goal of the seminar is to present and to discuss recent advances in the theory of decision procedures and to concentrate on its applications in various areas. A large number of highly interesting contributions were submitted for possible presentation at LINZ 2011. In order to maintain the traditional spirit of the Linz Seminars — no parallel sessions and enough room for discussions — we selected those twenty-eight submissions which, in our opinion, fitted best to the focus of this seminar. This volume contains the abstracts of this impressive selection. These regular contributions are complemented by six invited plenary talks, some of which are intended to give new ideas and impulses from outside the traditional Linz Seminar community.