Description:This book constitutes the refereed proceedings of the 7th International Conference on Integer Programming and Combinatorial Optimization, IPCO'99, held in Graz, Austria, in June 1999.The 33 revised full papers presented were carefully reviewed and selected from a total of 99 submissions. Among the topics addressed are theoretical, computational, and application-oriented aspects of approximation algorithms, branch and bound algorithms, computational biology, computational complexity, computational geometry, cutting plane algorithms, diaphantine equations, geometry of numbers, graph and network algorithms, online algorithms, polyhedral combinatorics, scheduling, and semidefinite programs.