The measurement of tumor cell proliferation is becoming inueasingly recognized in defining prognostic groups. Boliferatirg cell nuclear antigen(PCNA) imrnunolocalimtion can be used as an index of cell proliferation and rnay define the extent of deppature from norrmil gmwth control. PCNA is eonsidered to be maker of cell proliferation. The aim of this study was to evnlunte the expreeion of PCNA in epithelial ocarian cancer as well as the possible correlation with degree of differentiation, tumor etage and overall survival. The material consisted of 35 epithehal ovarian cancer. The PCNA labelling index (Ll) ranged from 7.5% to 92.5% with a median value of 46.7%. PCNA labelling index (LI) is 30% in grade 1, 63% in grade 2, and 100% in grade 3 in epithelial ovarian cancer(p>0.05). Also, a positive correlation was found between PCNA labelling index (LI) and clinical stage (P<0.05) The estimated 3 year survival in patients with a tumor LI below the median (low proliferative group) was higher than those with a tumor LI greater than the median(high proliferation group) (87.5% VS 50%, P<0.05).