This volume contains the proceedings of the 4th International Conference on Veri?cation, Model Checking, and Abstract Interpretation (VMCAI 2003), held in New York city, January 9-11, 2003. The purpose of VMCAI was to provide a forum for researchers from three communities-Veri?cation, Model Checking, and Abstract Interpretation-that will facilitate interaction, cross-fertilization, and the advance of hybrid methods that combine the three areas. With the g- wingneedforformaltoolstoreasonaboutcomplex, in?nite-state, andembedded systems, such hybrid methods are bound to be of great importance....