The traditional classification of infiltrating breast carcinomas into ductal and lobular can be diagnosticallychallenging in a small proportion of cases with equivocal histological features and in in-situ lesions withoverlapping features. Distinguishing between the infiltrating ductal (IDC) and lobular (ILC) carcinomas isclinically important because of the different pattern of systemic metastases and prognostic evaluation. E-cadherinis a potentially useful immunohistochemical marker which may serve to differentiate between the two tumourtypes. We therefore studied E-cadherin expression in 32 cases of breast carcinomas comprising 16 IDCs and 16ILCs. The correlation between E-cadherin expression and the histological grade of IDCs was also analysed. Ourresults showed complete loss of E-cadherin expression in all ILCs, while the IDCs consistently showed variableE-cadherin positivity. No significant correlation was found between E-cadherin expression and the histologicalgrade of IDCs. We conclude from this study that E-cadherin is a useful marker to differentiate between IDCand ILC of the breast. A larger study of IDCs is now needed to further evaluate the correlation between Ecadherinand tumour grade to estimate its prognostic potential.