Neoangiogenesis has been proved to be crucial in neoplasmatic tumor growth and metastases. Over the last few years, the factors that have both a positive (angiogenic) and negative (antiangiogenic) influence on tumor growth have been identified. The potential use of natural and synthetic factors that suppress vasculature formation as anticancer drugs is currently under intense investigation. Recently, several antiangiogenic compounds, including TNP-470 or matrix metalloproteinase inhibitors, have entered clinical trials. This review will describe the main groups of angiogenesis inhibitors, their mechanisms of action and some data from clinical studies.