This book constitutes the refereed proceedings of the 8th International Symposium on Functional and Logic Programming, FLOPS 2006, held in Fuji-Susono, Japan, in April 2006. The 17 revised full papers presented together with 2 invited contributions were carefully reviewed and selected from 51 submissions. The papers are organized in topical sections on data types, FP extensions, type theory, LP extensions, analysis, contracts, as well as Web and GUI.