Background Breast cancer is an epithelial malignancy; however, stroma plays a key role with its stimulatory and inhibitory factors in modulating tumor invasion and metastasis. CD10, a matrix metalloproteinase, is known to regulate cell adhesion, migration and helps in determining the progression of tumor. This knowledge helps to identify specific signals that promote growth, dedifferentiation, invasion, metastasis and serve as target for better therapeutic management. Objectives The aim of this study was to estimate frequency of expression of stromal CD10 and assess its prognostic significance in breast carcinomas by correlating with known prognostic factors. Materials and Methods Morphological parameters of 62 cases of carcinoma breast were studied on H&E (hematoxylin and eosin) stained sections and expressions of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu), and CD10 on manually constructed tissue microarray sections by immunohistochemistry (IHC). Staining pattern, percentage of stained cells, and intensity of stains were evaluated and IHC scoring of all markers was done. CD10 scores were correlated with the known prognostic factors (ER, PR, and HER2/neu). A p -value less than 0.05 was considered as significant. Results Stromal expression of CD10 was found in 82.3% of cases and it was significantly associated with increasing tumor size ( p = 0.012), increasing tumor grade ( p = 0.001), lymph node metastasis ( p = 0.018), necrosis ( p = 0.008), lymphovascular invasion ( p = 0.008), ER negativity ( p = 0.001), PR negativity( p = 0.007), HER 2 positivity ( p = 0.012), triple-negative molecular subtypes ( p = 0.001), and poor prognostic groups ( p = 0.01). Conclusion CD10 can be used as an independent prognostic stromal marker and this will help to envisage new therapeutic strategies.