Angiogenesis, the production of new blood vessels, plays an important role in a number of physiological and pathological processes, such as development, tissue repair, atherosclerosis, ischemic heart diseases, inflammation and tumor progression. A number of mediators including cytokines, heparin-dependent and -independent growth factors, proteolytic enzymes, extracellular matrix components, cellular adhesion molecules and others, have been implicated in angiogenesis. Certain angiostatic cytokines, growth factor antagonists, steroids, protease inhibitors, antibiotics, antirheumatic drugs, tissue-derived inhibitors and others inhibit neovascularization. Angiogenesis research has important clinical relevance, as targeting angiogenic and angiostatic processes by using angiogenesis inhibitors, receptor antagonists, antibodies, enzyme inhibitors, tumor suppressor genes and other forms of gene therapy, may be a potential therapeutic tool in "angiogenic diseases".