ABSTRACT: AIM:The objective of this study was to evaluate the prognostic value of ARID1A, p53, p21, p16 and ß-Catenin in endometrioid and clear cell ovarian and endometrial carcinomas. MATERIALS AND METHODS:97 tumors were available for analysis of ARID1A, p53, p21, p16 and ß-Catenin with the techniques of tissue microarray and immunohistochemistry. 32 were ovarian carcinomas and 65 were endometrial carcinomas. RESULTS:Endometrioid ovarian carcinomas showed negative staining for ARID1A (a) and p21 (b), aberrant expression of p53 (c) and p16 (d) and ß-Catenin positive nuclear expression (e) respectively in 19% (a), 100% (b), 28.6% (c), 52.4% (d) and 4.8% (e) of all cases. In the group of clear cell ovarian carcinomas it was 63.6% (a), 100% (b), 81.8% (c), 54.5% (d) and 0% (e). For endometrioid uterine carcinomas it was 75.7% (a), 94.9% (b), 30.5% (c), 52.1% (d) and 6.8% (e) and for clear cell uterine carcinomas it was 8.6% (a), 100% (b), 50% (c), 100% (d) and 0% (e). Survival analysis showed that negative expression of ARID1A, p53 aberrant expression and ß-Catenin nuclear positive staining are independent negative prognosticators in both, clear cell and endometrioid carcinoma, regardless of ovarian or uterine origin. Cox-Regression analysis showed them again as negative prognostic factors. Furthermore, we found a significant correlation between ARID1A and ß-Catenin expression in endometrioid uterine tumors. CONCLUSION:The analyzed gynaecological carcinoma showed a distinct expression scheme of proteins that are associated with tumor suppression. We may conclude that ARID1A, p53 and ß-Catenin are the strongest prognostic factors by analyzing a subgroup of tumor suppressor genes in clear cell and endometrioid subtypes of ovarian and endometrial cancer and may be used along with traditional morphological and clinical characteristics for prognosis.