Background: This study aimed to show the localization of estrogen / progesterone receptors, human epidermal growth factor receptor 2 (Her-2) and protein 53 (p53) by immunohistochemistry in a series of consecutive breast cancer patients. Materials and Methods: The study covered invasive breast cancers from 299 patients presenting at the Oncogenetic Clinic and Pathology Centers of Ahwaz Jondishapour University of Medical Sciences Hospital in Iran during the time period from 2009 to 2011. The Scarff-Bloom Richardson scoring method was used. Results: Of the 299, 27% (80/299) were <40, 33% (100/299) were 41-50, and the remaining 40% (119/299) were>50 years old. The highest incidence of breast cancer in this study population was in the group of more than 50 year age, and the most common histological type of breast cancer was the invasive ductal carcinoma, which accounted for 68% (203/299) of the cases. Out of possible total of 207, 6% (13/207), 41% (85/207), and 53% (109/207) were scored as grade I, II, III, respectively. Conclusion: Our findings demonstrated a lack of association between labeling for the markers studied and tumor size and age of the patients. We confirmed an association between ER labeling and nuclear grade of breast cancer. The conflicting results obtained compared with the literature be because of differences in the immunohistochemical techniques applied in the various studies and to the scoring systems used.