Wearedelightedtopresenttheproceedingsofthe5thInternationalWorkshopon Modeling Autonomic Communication Environments (MACE 2010). This wo- shopwasheldaspartofthe6thInternationalConferenceonNetworkandService Management (CNSM 2010), formerly known as and building on the success of the MANWEEK conference series. This year we met just a hundred yards away from Niagara Falls in Canada, a very exciting location. MACE started as an experiment and over the past years has created a small yet very active community that convened again this year to discuss and ev- uate new advances, innovative ideas, and solid developments. The main focus of MACE, combining modeling with communications, is certainly a hard topic that requires a lot of discussion, thus the work presented at the workshop is - trinsically debatable and might not be as practiced as in other well-established workshops, but this was the nature of MACE from the beginning. New ideas, sometimes more,sometimes less rougharoundthe edges (and someof them even inside) are submitted and provoke extensive discussions. The ?eld in which we areworkingreliesonthesediscussions,orevenadventures,andwehavethis year again strongly motivated and supported a variety of novel work in the technical program. This year, the submissions, while being closely related to the main themes, brought some new areas into the workshop. We still see architectural design and theapplicationofautonomicprinciplestonetworksandservices,butwealsonow have submissions looking into previously unexplored areas such as Home Area Networks,multimedia streaming,virtualization,federation,anduserexperience. This portrays a maturity in the domain, which has by now gone through several cycles, and improves its outputs by applying the lessons learned.