Introduction: Carcinoma breast is one of the commonest cancer in women, both in western world and in developing countries like India. Breast carcinoma is a hormone dependant disease. Immunohistochemical prognostic and predictive markers ER, PR and Her2/neu significantly influences prognosis, survival and selection of therapy in female breast cancer cases. Aim and objective: The purpose of this study was (i) to evaluate the prevalence of prognostic and predictive markers ER, PR and Her2/ neu by immunohistochemistry in female carcinoma breast cases in Bihar (Northern India), (ii) to compare the pattern of expression of these markers with age of the patients & (iii) to correlate the ER, PR & Her2/neu expressions with each other. Materials and Methods: This prospective study was carried out in Department of Pathology, Mahavir Cancer Sansthan and Research Centre, Phulwarisharif in between March 2015 to December 2016. 412 female carcinoma breast cases diagnosed by radiology and FNAC and further confirmed by histopathological examination of biopsy were included in this study. Immunohistochemical staining for ER, PR and Her2/neu were done in all 412 cases of female carcinoma breast. Results: Immunohistochemical markers ER and PR were found positive in 210 (50.97%) and 234(56.49%) cases respectively. Her2/neu was found positive in 148 (35.92%) cases. The Mean± SEM age of the patient in this study was 47.63 ± 0.549 years. Triple negative breast cancer which had poor prognosis was found in only 16 (3.88 %) cases. Conclusion: In conclusion, the prevalence of ER, PR and Her2/net over expression in our study does not fall within the ranges given in most of the literature. Our results showed higher proportion of ER, PR and Her2/ neu over expression in comparison to most of the studies. Fortunately our results also showed lower proportion of triple-negative breast cancer cases having poor prognosis. The findings suggest that North Indian women in the Bihar have breast carcinoma comparatively at younger age, likely to be more susceptible to conventional hormonal and targeted antibody treatment.