Description:This book constitutes the thoroughly refereed post-proceedings of the 4th Workshop on Model Checking and Artificial Intelligence, MoChArt IV, held in Riva Del Garda, Italy in August 2006, as a satellite event of ECAI0 2006, the 17th biannual European conference on Artificial Intelligence. The 8 revised full workshop papers and 3 revised post-proceedings papers presented have gone through two rounds of reviewing and improvement and were carefully selected for inclusion in the book. The workshop covers all ideas, research, experiments and tools that relate to both MC and AI fields. The papers are organized in topical sections on planning and model checking, heuristics for real-time model checking, verification of multi-agent systems, as well as logics for model checking and artificial intelligence.