Results from our studies on the clinical applicability of proliferation markers and growth factors in the histopathological assessment of malignancy and prognosis of ovarian neoplasms are presented. Bromodeoxyuridine incorporation, Ki 67 antigen visualization and proliferation cell nuclear antigen expression indicated location and extent of cell proliferation, though not uniformly as compared to flow cytometry and mitotic counting. Clinicopathological correlations of the occurrence of programmed cell death, apoptosis, as indicated by morphology gave inconclusive results, as did analysis of Bcl-2 expression. Increased visualization of p53 protein was associated with increased degree of malignancy but was inconsistent in individual specimens. Growth factor expression, in particular transforming growth factor beta staining intensity, gave additional information on cell behaviour as did vascular endothelial growth factor distribution on vascularization and vessel neoformation when compared to platelet derived growth factor expression, useful in isolated specimens, and to basic fibroblast growth factor expression. The markers presented are indispensible in certain tumour types and give additional information improving our understanding of ovarian neoplasms and tumour classification in general but are mostly not yet reliable enough for clinically applicable conclusions of individual patients.