This volume contains the proceedings of the 24th IFIP TC 6/WG 6.1 Inter- tionalConference onFormalTechniquesfor Networkedand Distributed Systems (FORTE 2004),held in Madrid, Spain, September 27-30,2004.FORTE denotes a series of international working conferences on formal description techniques applied to computer networks and distributed systems. The conference series started in 1981 under the name PSTV. In 1988 a second series under the name FORTE was set up. Both series were united to FORTE/PSTV in 1996. Three years ago the conference name was changed to its current form. The last ?ve meetings of this well-established conference series were held in Beijing, China (1999), Pisa, Italy (2000), Cheju Island, Korea (2001), Houston, USA (2002), and Berlin, Germany (2003). The scope of the papers presented at FORTE 2004 covered semantic models and application of formal description languages (in particular, automata and Petri Nets), as well as the veri?cation and testing of communication and d- tributedsystems.Theconferencewasprecededby2half-daytutorialsbyRoberto GorrieriandFarnWang.Theproceedingscontainthe20regularpapersaccepted and presented at the conference. They were selected from 54 submitted papers inacarefulselectionprocedurebasedontheassessmentofthreerefereesforeach paper. The proceedings also include the papers contributed by the three invited speakers: Mart' ?n Abadi, Tommaso Bolognesi, and Juan Quemada.