This study investigated the relation between immunohistochemical prognostic factors and clinical stage and histopathological grade in endometrial adenocarcinoma. Twenty-seven patients with a mean age of 61 (38-74), who underwent radical surgery due to endometrial adenocarcinoma in our hospital between 1983-1998, were re-evaluated. For clinical staging FIGO criteria were used. Histopathological differentiation of the tumor was graded as good (grade 1), moderate (grade 2), and poor (grade 3). Estrogen and progesterone receptors, c-erb B2, UEA 1, Ki-67, PCNA and p53 were studied as immunohistochemical prognostic factors. There were no patients in stages IA and IIIB. Among the prognostic factors, PCNA was the most significantly stained marker, followed by c-erb B2, estrogen and progesterone receptors, regardless of the clinical stage and histopathological grade of the tumor. The least positivity was achieved with Ki-67. There was no significant difference when each prognostic factor was analysed with respect to clinical stage and histopathological grade. In our study no significant relation was found between the prognostic factors and the clinical stage and histopathological differentiation of the tumor. Therefore the cost effectiveness of the utilization of these factors should be reconsidered.