This book constitutes the refereed proceedings of the 6th International Symposium on Functional and Logic Programming, FLOPS 2002, held in Aizu, Japan, in September 2002. The 15 revised full papers presented together with 3 full invited papers were carefully reviewed and selected from 27 submissions. The papers are organized in topical sections on constraint programming, program transformation and analysis, semantics, rewriting, compilation techniques, and programming methodology.