BACKGROUND Breast cancer is the foremost cause of death in women worldwide with more than one million cases occurring annually. OBJECTIVE This study was conducted to study the stromal CD10 expression in breast carcinomas (BCa) and its correlation with various prognostic factors such as tumor size, histological grade, lymph node status, estrogen receptor (ER), progesterone receptor (PR), HER2neu, and Ki67 status. METHODS Sixty cases of BCa diagnosed between 2013 and 2015 were included in the study. Stromal expression of CD10 was studied on entire section of selected BCa blocks for all cases. A technique of manual tissue microarray was employed for the analysis of expression of immunohistochemical markers ER, PR, and HER2/Neu and Ki67 in all cases. Results were subjected to statistical analysis. RESULTS Stromal CD10 positivity was seen in 78.3% cases, out of which 53.3% of cases were strongly positive, and 25.0% cases were weakly positive. Positivity for ER, PR, HER2, and Ki67 was 31.7%, 33.3%, 65%, and 75%, respectively. Stromal expression of CD10 was found to be significantly associated with increasing tumor grade, lymph node status, HER2neu positivity, ER negativity, and Ki67 positivity. CD10 stromal expression was seen mainly in PR negative BCa cases; however, it was statistically insignificant. It was noted that CD10 stromal positivity increased with increasing grade. CONCLUSIONS CD10 can be used as an independent prognostic marker and should be included in routine histopathology report. CD10 could act as a potential target for newer drug development.