The 13th International Conference on Principles and Practice of Constraint Programming (CP 2007) was held in Providence, RI, USA, September 23–27, 2007, in conjunction with the International Conference on Automated Pl- ning and Scheduling (ICAPS). Held annually, the CP conference series is the premier international conference on constraint programming. The conference focuses on all aspects of computing with constraints. The CP conference - ries is organized by the Association for Constraint Programming (ACP). - formation about the conferences in the series can be found on the Web at http://www. cs. ualberta. ca/~ai/cp/. Information about ACP can be found athttp://www. a4cp. org/. CP 2007 launched two calls for contributions: a call for research papers, describing novel contributions in the ?eld, and a call for application papers, describing applications of constraint technology in the industrial world. The research track received 143 submissions and the application track received 22 submissions. Research papers were reviewed under a double-blind scheme. They received three reviews that the authors had the opportunity to see and to react tobeforethepapersandtheirreviewswerediscussedextensivelybythemembers of the ProgramCommittee. Application papers werereviewedby a separate- plication Committee. The Program Committee and the Application Committee then selected 43 researchpapers and 9 application papers to be published in full inthe proceedings,andanadditional14researchpapersto be publishedas short papers. The full papers were presented at the conference in two parallel tracks and the short papers were presented in a poster session.