BACKGROUND Ovarian tumours are the common cause of morbidity and mortality in women worldwide. Primary epithelial ovarian tumours comprise the majority. Cluster differentiation 44 (CD-44) is a trans-membrane glycoprotein which plays a role in cell- cell interaction, adhesion and migration, leading to the progression and metastasis of tumour. E-cadherin is another cell adhesion molecule which plays an important role in neoplastic progression. So, it is necessary to find out the relationship of CD-44 and E-cadherin expression with histological types and tumour differentiation, which might predict the prognosis. The present study was undertaken to assess the pattern of expression of CD-44 and E-cadherin in primary epithelial tumours of ovary and to determine the relationship between their expression with age, histological type and tumour differentiation. METHODS This is a cross-sectional study conducted in the Department of Pathology, Government Medical College, Thrissur; a tertiary care institution. Histological types and tumour differentiation for each case was determined from haematoxylin and eosin sections. Immunohistochemical stain for CD-44 and E-cadherin was done. Pattern of expression was studied and a semi quantitative score was calculated. Expression of both markers was then compared with the age, histological type and tumour differentiation. RESULTS Out of 57 cases studied, majority of the patients had serous (21 cases) or mucinous tumours (20 cases). The mean age group was 54.5 years. CD-44 expression was significantly correlated with tumour differentiation but there was no correlation found with age and histological type. In E-cadherin expression, there was no correlation with age, histological type and tumour differentiation. CONCLUSIONS For primary epithelial tumours, expression of CD-44 could be an indicator for tumour progression, invasiveness or distant metastasis. Poorly differentiated tumours with increased expression may be helpful in predicting disease progression. Target therapy can be employed in such cases. In case of E-cadherin which is said to be a prognostic marker, more studies help in bridging the gap between prognosis and outcome. KEYWORDS CD-44, E-cadherin, Immunohistochemistry, Epithelial Ovarian Tumours f