This volume contains the proceedings of the 1998 international symposium on staticanalysis(SAS'98)whichwasheldinPisa(Italy),onSeptember14-16,1998 and was part of a federated conference with ALP-PLILP'98 and several wo- shops. SAS'98isthe annualconferenceandforumforresearchersinallaspectsof staticanalysis. ItfollowstoSAS'94,SAS'95,SAS'96andSAS'97whichwereheld respectively in Namur (Belgium), Glasgow (UK), Aachen (Germany) and Paris (France), and the international workshops WSA'92 held in Bordeaux (France) and WSA'93 held in Padova (Italy). In response to the call for papers, 48 papers were submitted. All papers were reviewed by at least three reviewers and the program committee met in Pisa to select 20 papers based on the referee reports. There was a consensus at the meeting that the technical papers were of very high quality. In addition to the submitted papers, SAS'98 had a number of outstanding invited speakers. Roberto Giacobazzi, Peter Lee, Amir Pnueli, Dave Schmidt, Scott Smolka, and Bernhard Ste?en accepted our invitation to give invited talks or tutorials. Some ofthepapers(orabstracts)basedonthesetalksarealsoincludedin thisvolume. SAS'98 has been fortunate to rely on a number of individuals and orga- zations. I want to thank all the program committee members and referees, for their hard work in producing the reviews and for such a smooth and enj- able programcommittee meeting. Special thanks go to the conference chairman, Maurizio Gabbrielli, and to my students in Pisa who helped me a lot. More s- cial thanks go to Vladimiro Sassone, who made available to SAS'98 his excellent system for handling submissions and reviews on the web, and to Ernesto Lastres andRen` eMorenowhoweremy"systemmanagers".