The present study was aimed to evaluvate the apoptogenic potential of ethanolic extract of leaves from Boswellia ovalifoliolata (BL EthOH) and to unravel the molecular mechanisms implicated in apoptosis of Triple Negative Breast Cancer (TNBC) cells. BL EthOH was cytotoxic against TNBC cells like MDA-MB-231 and MDA-MB-453 with IC₅₀ concentrations 67.48 ± 5.45 and 70.03 ± 4.76 μg/ml, respectively. Apoptotic studies showed that BL EthOH was able to induce apoptosis and western blot studies demonstrated that BL EthOH significantly decreased the Phospho-NF-κB (ser536), PCNA, anti-apoptotic protein Bcl-2 expression and increased the expression of pro-apoptotic protein Bax, in MDA-MB-231 and MDA-MB-453 cell lines when compared with untreated cells. Besides, BL EthOH has synergistic chemosensitizing effects on TNBC cells and increased the cytotoxicity of doxorubicin and cisplatin.