Purpose <p>A novel and potential target for immunotherapy in a variety of malignancies is the PD-L1/PD-1 (Programmed Death Ligand) pathway. Triple negative breast cancer, an aggressive form of carcinoma breast, is thought to involve immune system because of the activation of numerous genes linked to immune function. Previous studies on PD-L1 expression in TNBC have shown varied results. Our objective was to determine the immunohistochemical expression of PD-L1 in TNBC and its relation with different clinico-pathological characteristics.</p> Methods <p>A total of 34 breast cancer specimens diagnosed as TNBC were studied. The slides of haematoxylin and eosin, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 and Ki-67 were reviewed. Clinico-pathological data of the cases were also documented. PD-L1 IHC staining was done on tumor sections. The expression of PD-L1 was assessed on tumor cells and immune cells that had infiltrated tumors, and was correlated with various clinico-pathological parameters.</p> Results <p>PD-L1 positivity on tumor cells and immune cells were evaluated using different scoring systems. The PD-L1 expression on tumor cells strongly correlated with immune cell infiltration and histopathological type (<i>p</i> value &lt; 0.05) whereas immune cell PD-L1 expression correlated with the location of the tumor and histopathological type (<i>p</i> value &lt; 0.05). A combined tumor cell and immune cell score (TCIC) was significantly associated with tumor location (<i>p</i> value &lt; 0.05). However, PD-L1 expression did not correlate with any other prognostic variables.</p> Conclusion <p>Histological type, immune cell infiltration, and tumor location were significantly linked with PD-L1 expression. These features may be useful in identifying TNBC cases with a high likelihood of PD-L1 expression.</p>