INTRODUCTIONBreast cancer originates most commonly from the inner lining of milk ducts or the lobules that supply the ducts. Cancers originating from ducts are known as ductal carcinomas, while those originating from lobules are known as lobular carcinomas. Carcinoma breast is the commonest malignancy of females all over the world and second leading cause of death due to cancer among females. Worldwide, breast cancer accounts for 22.9% of all cancers (excluding non-melanoma skin cancers) in women.2 Prognosis and survival rates for breast cancer vary greatly depending on the cancer type, stage, treatment, and geographical location of the patient.The proto-oncogene HER-2/neu (C-erbB-2) has been localized to chromosome 17q and encodes a transmembrane tyrosine kinase growth factor receptor. The name for the HER-2 protein is derived from human epidermal growth factor receptor, as it features ABSTRACT Background: Tumours that over express HER2/neu are less responsive to chemotherapy and patients with these tumours have a reduced survival compared with patients with normal levels of HER2/neu. The aim was to determine the frequency of HER-2/neu receptor over-expression in Breast cancer patients and its comparison to Her-2/neu negative breast cancer in respect to clinical presentation, risk factors, clinical staging, pathological staging. Methods: 50 patients who presented with Invasive ductal carcinoma of breast, meeting inclusion and exclusion criteria were included in the study. They were divided into two groups; according to Her-2/neu receptor overexpression (Yes/No).Incidence of Her-2-neu receptor over-expression was determined among the sample population. Both groups were compared on the basis of various parameters. Results: Young age at presentation, negative hormone receptor status (ER/PR), high grade of tumour, large sized tumour and increased axillary lymph nodes are more common in Her-2/neu over-expression patients. These parameters are statistically significant. Conclusions: Her-2/neu overexpressing breast cancers have increased invasive and metastatic capability and are less responsive to chemotherapy. They have increased risk of recurrence and patients with these tumours have a reduced survival compared with patients with normal levels of HER2/neu.