The capacity to induce growth of blood vessels represents one of the phenotypic traits of neoplastic cells. Several preclin­ical studies prove that the inhibition of growth of peri-neoplastic blood vesssels leads to restricted growth of primary tumours and of metastases. Nevertheless, clinical studies indicate that angiogenesis inhibitors are not such effective drugs as might be expected on the basis of studies conducted on animals. In this article we would like to draw the readers' attention to diver­gencies between preclinical and clinical results, in particular to those related to ovarian cancers. In the treatment of ovarian cancers, angiogenesis inhibitors combined with other drugs may prove to represent a relatively effective therapeutic approach.