Tumors, like other tissues, have a fundamental requirement for access to the nutrients, oxygen and waste removal functions of the circulatory system. Vascular targeted therapy exploits this basic need, along with molecular heterogeneity observed between normal and tumor blood vessels, to develop efficient and selective chemotherapies that essentially starve tumors by destroying their vasculature. As the basic principle on which this therapy is based differs from agents that directly target cancerous cells, combining it with traditional therapies such as radiation, surgery and existing chemotherapies has the potential to create powerful new anticancer strategies. As the requirement for vascularization is universal to solid tumors, vascular targeted therapies have the potential for broad applicability. Vascular targeted therapies include both angiogenesis inhibitors, which inhibit neovascularization, and vascular disrupting agents, which destroy existing vasculature. Applications of this model include finding peptides that bind specifically to cell surface markers on tumor vessel endothelial cells and might deliver chemotherapeutic agents. Expression profiling with microarrays, serial analysis of gene expression, and in vitro and in vivo screening of phage display libraries have identified candidate peptides for targeted delivery to the tumor endothelium.