ThisvolumecontainstheproceedingsoftheconferenceonComputer AidedVe- ?cation, CAV 2004,held in Boston,Massachusetts,USA, July13-17,2004.CAV 2004 was the 16th in a series of conferences dedicated to the advancement of the theory and practice of computer-assisted formal analysis methods for software and hardware systems. The conference covers the spectrum from theoretical - sults to concrete applications, with an emphasis on practical veri?cation tools and the algorithms and techniques that are needed for their implementation. The conference has traditionally drawn participation from researchersas well as practitioners in both academia and industry. CAV 2004 was colocated with the ACM International Symposium on So- ware Testing and Analysis (ISSTA 2004), and was partially sponsored by the ACMSIGSOFT.Thecolocationre?ectstheincreasingsynergybetweenresearch on veri?cation and testing, and emerging applications of formal veri?cation to softwareanalysis.Joint CAV-ISSTA events included a distinguished plenary l- ture by David Harel and a special session exploring various approaches to the speci?cation and veri?cation of concurrent software organized by Shaz Qadeer.