th This volumecontains the proceedingsof the 9 internationalconference onV- i?cation, Model Checking, and Abstract Interpretation (VMCAI 2008), held in San Francisco, January 7-9, 2008. The purpose of VMCAI is to provide a forum for researchers from three communities-Veri?cation, Model Checking, and - stractInterpretation-thatwill facilitate interaction, cross-fertilization, andthe advance of hybridmethods that combine the three areas.With the growingneed for formal tools to reason about complex, in?nite-state, and embedded systems, such hybrid methods are bound to be of great importance. Topics covered by VMCAI include program veri?cation, program certi?- tion, model checking, debugging techniques, abstract interpretation, abstract domains, static analysis, type systems, deductive methods, and optimization. VMCAI 2008 was the 9th VMCAI meeting. Previous meetings were held in Port Je?erson 1997, Pisa 1998, Venice 2002, New York 2003, Venice 2004, Paris 2005, Charleston 2006, and Nice 2007. The program committee selected 21 papers out of over 60 on the basis of at least three reviews. The principal criteria were relevance and quality. The program of VMCAI 2008 included, in addition to the research papers, three invited talks, by Radhia Cousot, Maurice Herlihy and Neil Jones, and three tutorials, by Orna Kupferman, Jens Palsberg, and Marco Pistoia. We would like to thank the ProgramCommittee members and the reviewers, without whose dedicated e?ort the conference would not have been possible. Our thanks also to the Steering Committee members for their helpful advice.