The aim of the study was the analysis of the new molecular genetic immunomarkers (p53, c-erbB-2, Ki 67, bcl-2) hormonal receptors (ER, PR) and ploidy disturbances and their relation to the most important prognostic factors for endometrial cancer. The study group consisted of 135 endometrial cancer patients. Biopsies of the tumours obtained at operations were routinely histopathologically examined. Subsequenly, the immunohistochemical tumour markers were determined. The same biopsies were examined by microdissection and flow cytometric ploidy analysis and karyotyping. The findings were compared with the most important prognostic factors for endometrial cancer, mainly with clinical stage of the disease and grade. Results: High expression of p53, Ki 67, c-erbB-2 and low rate of progesterone receptors was found in the prognostically unfavourable group (G 3). Aneuploidy was found in 72% in the group of poorly differentiated endometrial cancers (G 3) in contrast to 27% in the group of G1 and G2 tumours, but this difference was not statistically significant. Conclusions: Identification of p53, Ki 67, c-erbB-2, PR and determination of DNA ploidy is a useful tool to specify a group of prognostically unfavourable patients.