Background and objective: Mutations of the P53 tumor suppressor gene and altera-tions in its protein expression often occur in a variety of human malignant tumors, including endometrial carcinoma, but the practical implications of this phenomenon are yet to be fully exploited. This study was designed to evaluate P53 protein expression in normal, hyper-plastic and malignant endometrium by immunohistochemical study and to correlate P53 expression in endometrial carcinoma with other clinic-pathological prognostic parameters (age, histologic type, tumor grade, cervical & myometrial invasion, and tumor stage). Methods: The studied samples included 100 formalin fixed, paraffin embedded endo-metrial tissue specimens which were divided to the following diagnostic categories: - Pro-liferative endometrium (n=10); secretory endometrium (n=10); simple hyperplasia (n=10); complex hyperplasia without atypia (n=20); atypical complex hyperplasia (n=10) and endo-metrial carcinoma (n=40). Results: None of the normal endometrium, simple hyperplasia and complex hyperplasia without atypia showed P53 immunostaining, while 20% of atypical complex hyperplasia and 32.5% of endometrial carcinoma showed immunoreactivity for P53. In endometrial car-cinoma, significant correlation was observed between P53 expression and age at diagno-sis, histological grade,FIGO stage, myometrial invasion & cervical invasion ; but not with the histological type . Conclusion: The results indicated the validity & simplicity of the application of immuno-histochemistry in determining the status of P53 overexpresion which is strongly associated with endometrial carcinoma aggressiveness and high malignant potential.