Two processes are necessary for a tumor colony to grow and become invasive: angiogenesis and basement membrane degradation. Angiogenesis is the formation of new blood vessels from the endothelium of existing vasculature, in response to the metabolic demand of the tumor. Assessment of the degree of tumor angiogenesis may improve risk stratification in patients with lung cancer, especially those with early-stage disease. In addition, the strategy of blocking the mechanism of angiogenesis may prove to be an effective therapeutic alternative for patients with nonsmall cell lung cancer. Clinical trials evaluating novel antiangiogenic agents, including antibodies to vascular endothelial growth factor (VEGF) and compounds directed at the tyrosine kinase receptor, are ongoing.