Angiogenesis is a rapidly growing research field. Most of the important vascular growth factors have been identified in the space of a few years, as well as factors responsible for the diferentiation of arteries, veins and lymphatic vessels. The role of angiogenesis in tumor growth, exsudative retinopathies and some inflammatory diseases has been established in animal models and in the clinical setting Angiogenesis is necessary for oxygen and nutrient delivery to tissues. Hypoxia is a major determinant of angiogenesis. During adult life the vascular network is remarkably stable and there is no active angiogenesis. The endothelium is quiescent, except in some physiological circumstances such as the female reproductive cycle and muscular exercise The same molecular and cellular mechanisms as those that occur during embryonic angiogenesis are involved in physiological and pathological neoangiogenesis. Vascular endothelial growth factor (VEGF) plays a major role, and VEGF inhibition is a promising therapeutic approach to some tumoral and ocular diseases.