The proportion of vascular elements in relation to the parenchymal and stromal components was determined by morphometric analysis of the histologic preparations from biopsies of [human] uterine cervix cancers. The material was obtained from tumors in stages Ib and IIa before any therapy was initiated. In the 23 cases in which radiation treatment of the lesions resulted in a survival > 5 yr, the proportion of blood vessels in the neoplastic tissue was larger; the stromal components were especially richer in vascular elements compared to the 22 cases in which survival was < 5 yr. Vascular density in cervical cancers of the stages studied apparently can be a diagnostic parameter of prognostic and therapeutic values.