The Workshop on Approximation Algorithms for Combinatorial Optimization Problems APPROX 2002 focused on algorithmic and complexity aspects ar- ing in the development of e?cient approximate solutions to computationally d- ?cult problems. It aimed, in particular, to foster cooperation among algorithmic and complexity researchers in the ?eld. The workshop, held at the University of Rome La Sapienza, Rome, Italy, was part of the ALGO 2002 event, in conju- tion with ESA 2002 and WABI 2002. We would like to thank the local organizers at the University of Rome La Sapienza for this opportunity. APPROX is an - nual meeting, with previous workshops in Aalborg, Berkeley, Saarbruc .. ken, and Berkeley. Previous proceedings appeared as LNCS 1444, 1671, 1913, and 2129. Topics of interest for APPROX 2002 were: design and analysis of approxi- tion algorithms, inapproximability results, on-line problems, randomization te- niques, average-case analysis, approximation classes, scheduling problems, ro- ing and ?ow problems, coloring and partitioning, cuts and connectivity, packing and covering, geometric problems, network design, applications to game theory, and other applications. The number of submitted papers to APPROX 2002 was 54 from which 20 papers were selected. This volume contains the selected papers together with abstracts of invited lectures by Yuval Rabani (Technion) and R.