These proceedings contain papers from the 27th FORTE conference. FORTE (Formal Techniques for Networked and Distributed Systems) is the joint int- national annual conference combining the former PSTV (Protocol Speci?cation Testing and Veri?cation) and former FORTE (Formal Description Techniques for Distributed Systems and Communication Protocols) conferences. The ?rst PSTV conference took place in 1981, and the ?rst FORTE took place in 1988. They were merged into one larger conference in 1996 and have run under the name of FORTE from 2001. The conference is a forum for presentation and d- cussion of the state of the art in theory, application, tools, and industrialization of formal methods. Over the years, FORTE has been held in numerous lo- tions, and this is re?ected by its recent history, with meetings in Pisa (Italy), Cheju Island(Korea),Houston(USA), Berlin(Germany),Madrid(Spain), Paris (France), Taiwan and now Tallinn, Estonia. FORTE was sponsored by Working Group 6.1 of Technical Committee 6 (TC6) of the InternationalFederation for Information Processing (IFIP). Indeed FORTE is one of the ?agship conferences of Working Group 6.1 (Architectures and Protocols for Distributed Systems), and covers many aspects of the main themes of WG6.1, namely, formal description techniques, open distributed s- tems, and quality of service. WG6.1 provided a Best Paper Award as well as funds to help student participation, and we are particularly grateful for this. The 27th FORTE conference was held during June 26–29, 2007, in Tallinn (Estonia), in the historical building of the Brotherhood of the Black Heads.