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...