This volumecontainsa selectionofthe the paperspresentedatthe 17thInter- tional Symposium on Logic-Based Program Synthesis and Transformation, that was held in KongensLyngby, Denmark, August 23-24,2007. Previous LOPSTR symposia were held in Venice (2007 and 1999), London (2005 and 2000), Verona (2004), Uppsala (2003), Madrid (2002), Paphos (2001), Manchester (1998, 1992 and 1991), Leuven (1997), Stockholm (1996), Arhhem (1995), Pisa (1994) and Louvain-la-Neuve (1993). The aim of the LOPSTR series is to stimulate and promote international research and collaboration on logic-based program development. LOPSTR thus traditionally solicits papers in the areas of: speci?cation, synthesis, veri?cation, transformation,analysis,optimization,composition,security,reuse,applications andtools,component-basedsoftwaredevelopment,softwarearchitectures,age- based software development and program re?nement. Formal proceedings are produced only after the symposium, so that authors can incorporate this fe- back in the published papers. Thirty submissions were received and each - per, in turn, received at least three reviews. The Committee decided to accept seven full papers for presentation and for immediate inclusion in the ?nal po- conference proceedings. Nine extended abstracts were also selected for pres- tation, of which six papers were accepted for publication in this volume, after revision and another round of reviewing. Michael Codish contributed a paper to the proceedings to accompany his invited talk. I am very grateful to the Program Committee and the reviewers for their - valuable help and expertise. The Steering Committee and, in particular German ‘ Puebla,generouslysharedtheirexperience.