To test the association of endometrial cancer with the p73 G4C14-to-A4T14 polymorphism in exon 2 and the p53 Arg72Pro polymorphism, an incident case-control study was performed in Japanese subjects. The cases comprised 114 endometrial cancer patients, and the controls were 320 healthy females and 122 noncancer female outpatients. An unconditional logistic regression model demonstrated a significant association between the p73 AA genotype and an increased risk of endometrial cancer (OR=2.82, 95% CI=1.36-5.82), especially of type-I tumors (OR=3.24, 95% CI=1.53-6.87). In contrast, there was no significant difference in the p53 Arg72Pro genotype frequency between the controls and cases.