Angiogenesis, the formation of new blood vessel networks to permit sustained tumor growth, is one of the most rapidly growing fields in basic and applied cancer research. Angiogenesis is a prerequisite for tumor growth and metastasis. Vascular endothelial cell proliferation, migration and capillary formation are stimulated by angiogenic growth factors. It is now accepted, mainly on the basis of knock-out experiments, that the most potent pro-angiogenic factor is the vascular endothelial growth factor (VEGF). VEGF is the prototype of a family of pro-angiogenic peptides, which now comprises several related members. Recent studies in gynecological oncology have shown considerable importance of tumor angiogenesis as independent prognostic factor, or the use of angiogenesis-related factors as possible tumor markers. Immunohistochemical studies have revealed that high microvessel density (MVD) was associated with poor prognosis in carcinomas of the uterine cervix, endometrium, vulva and ovary. Tumor angiogenesis is not a specific process for one type of tumor, and angiogenic growth factors cannot be specific for one type of malignant disease. Immunohistochemical studies also showed importance of angiogenic factors and MVD in other kinds of cancers such as breast cancer, gastrointestinal cancers, soft-tissue sarcomas etc. The importance of tumor angiogenesis in the natural history of cancer, the possible applications of angiogenesis markers as prognostic factors and the emergence of innovative antitumor treatments based on anti-angiogenic strategies may lead to new goals in oncology.