This volume contains the papers accepted for publication at IPCO X, the Tenth InternationalConferenceonInteger ProgrammingandCombinatorialOptimi- tion, held in New York City, New York, USA, June 7-11, 2004.The IPCO series of conferences presents recent results in theory, computation and applications of integer programming and combinatorial optimization. These conferences are sponsoredby the Mathematical ProgrammingSociety, andareheldin thoseyearsin whichno InternationalSymposiumonMathema- calProgrammingtakes place.IPCO VIII was held in Utrecht (The Netherlands) and IPCO IX was held in Cambridge (USA). A total of 109 abstracts, mostly of very high quality, were submitted. The ProgramCommittee accepted 32, in order to meet the goal of having three days of talks with no parallel sessions. Thus, many excellent abstracts could not be accepted. The papers in this volume havenot been refereed. It is expected that revised versions of the accepted papers will be submitted to standard scienti?c journals for publication. The Program Committee thanks all authors of submitted manuscripts for their support of IPCO.March 2004 George Nemhauser Daniel Bienstock Organization IPCO X was hosted by the Computational Optimization Research Center (CORC), Columbia University.