Angiogenesis, the process of new blood vessel development, is an essential component of the body's physiology and contributes to the pathogenesis of a variety of diseases such as benign and malignant neoplasia and rheumatoid arthritis. Failure of this physiological response is also important in abnormalities of wound healing in diseases such as duodenal ulceration and diabetes. Angiogenesis is controlled by a variety of factors that initiate, control and terminate this complex, multi-stage process. This review covers those factors that are exciting much interest currently and have potential for incorporation into clinical medicine.