Description:This book constitutes the thoroughly refereed and extended post-proceedings of the 11th Annual ERCIM International Workshop on Constraint Solving and Constraint Logic Programming, CSCLP 2006, held in Caparica, Portugal in June 2006. Besides papers taken from the workshop, others are submitted in response to an open call for papers after the workshop. The 10 revised full papers presented together with a tutorial on hybrid algorithms were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on global constraints, search and heuristics, language and implementation issues, and modeling.