OBJECTIVE To observe the relationship between suppressor gene p53 expression and endometrial carcinoma. METHODS Expression of p53 was studied by immunohistochemistry in paraffin sections from 23 normal endometrium, 44 endometrial hyperplasia and 103 endometrial carcinoma. RESULTS Immunohistochemical staining of p53 protein was negative in normal and hyperplastic endometrium but positive in 47.6% of endometrial carcinoma. In endometrial carcinoma, p53 over expression was significantly associated with histologic type, tumor grade, presence of vascular invasion and DNA aneuploidy. The survival rate of patients with p53 expression is significantly lower than that of patients without p53 expression (P < 0.001), the 5-year survival rate is 59.9% and 83.4% respectively. Patients with expression of mutant forms of the tumor suppressor gene p53 products had a 6.34-fold increased risk of death as compared with patients without p53 expression by Cox proportional hazards model. CONCLUSIONS Aberrant expression of p53 gene is indicative of aggressive biological behavior and poor survival in endometrial carcinoma.