This book constitutes the refereed proceedings of the Third IEEE International Workshop on Modelling Autonomic Communications Environments, MACE 2008, held on Samos Island, Greece, on September 22-26, 2008, as part of the 4th International Week on Management of Networks and Services, Manweek 2008.The 8 revised full papers and 4 revised short papers presented were carefully reviewed and selected from 22 submissions. The papers are organized in topical sections on autonomic networks, experiences and frameworks; strategies, processes and generation of components; capabilities; and short papers, early work and applied studies.