The polymorphism of codon 72 in the p53 tumour suppressor gene has been associated in the last decade with the risk of developing various neoplasias. An influence of this polymorphism on ovarian and endometrial cancer has also been suggested. We examined the genotype frequency of this polymorphism in archival samples from 56 patients with endometrial neoplasias and 51 patients with ovarian neoplasias. Cervical smears from 30 healthy, human papillomavirus (HPV)-negative women with normal cytology and colposcopy, served as control sample. Women with ovarian neoplasias, especially adenocarcinomas, had Arg/Arg more often than healthy controls [odds ratio (OR) 4.16 at P = 0.0058]. No statistically significant difference was found between women with endometrial cancer and controls. Differentiation of ovarian tumours did not appear to be associated in a statistically significant manner with the genotype, whereas a positive linear trend of Arg/Arg towards poor differentiation was noted in endometrial malignancies (mainly endometrioid adenocarcinomas). Our results suggest that homozygous arginine at codon 72 of p53 may represent a risk factor for developing ovarian malignancies and may affect the differentiation of endometrial cancer. Further studies need to be carried out in order to establish the clinical use of this polymorphism for risk assessment and possibly outcome prediction of ovarian and endometrial neoplasias.