The overexpression of two growth factor receptors - epidermal growth factor receptor (EGFR) and c-erbB-2 - was evaluated immunohistochemically in malignant and benign ovarian neoplasms, considering the stage of the disease and histology of tumors. The comparison of EGFR and c-erbB-2 reactivity in tissue sections and respective cyst and/or ascitic fluid cells was also performed. c-erbB-2 expression was detected in 44.4% of ovarian carcinomas, and in benign neoplasms there was no evidence of its staining, while EGFR reactivity was found both in malignant (58.7%) and benign (50%) tumors. Significant heterogeneity of staining was observed, however, the relationship between EGFR and c-erbB-2 expression in tissue sections and cyst and/or ascitic fluid cells in individual patients was evident. The expression of both growth factor receptors was not correlated with histopathological subtypes of ovarian neoplasms. The c-erbB-2 oncoprotein was detected more frequently in III/IV than in I/II stages according to the criteria of the International Federation of Gynecology and Obstetrics (FIGO) and the EGFR expression was independent of the clinical advancement of the disease. The coexpression of c-erbB-2 and EGFR was shown in 32% of ovarian carcinomas, and it dominated in cases with FIGO stages III/IV. Our results indicate that the increase of the EGFR expression appears to be associated with early stages of ovarian tumorigenesis, and the enhancement of c-erbB-2 reactivity may cooperate with EGFR activation in the development and progression of ovarian carcinomas.