This book constitutes the reviewed proceedings of the 8th International Conference on Integer Programming and Combinatorial Optimization, IPCO 2001, held in Utrecht, The Netherlands in June 2001. The 32 revised full papers presented were carefully reviewed and selected from a total of 108 submissions. The proceedings reflect most current directions in integer programming and optimization research. Among the topics covered are approximation algorithms, branch and bound algorithms, computational biology, computational complexity, algorithmic geometry, cutting plane algorithms, diophantine equations, geometry of members, graph and network algorithms, online algorithms, polyhedral combinatorics, scheduling theory and algorithms, and semidefinite programs.