Background/Aim: Triple-negative breast cancer (TNBC) is the most fatal form of breast cancer due to the shortcomings of therapies. However, recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL) is a promising anticancer therapeutic that possesses the capability to promote the induction of apoptosis in cancer cells, but some TNBCs are resistant to rhTRAIL's pro-apoptotic effects. Therefore, a combinatorial treatment approach with silibinin and rhTRAIL was considered in order to sensitize rhTRAIL-resistant TNBCs. Materials and Methods: The co-treatment of rhTRAIL and silibinin's impact on apoptosis induction in rhTRAIL-resistant TNBC BT-20 and HCC1937 cells was inspected via application of Annexin V/PI assays and western blot analysis. Results: Silibinin possessed the ability to sensitize the examined rhTRAIL-resistant TNBC cells to rhTRAIL-induced apoptosis through the up-regulation of death receptors 4 and 5 and the down-regulation of survivin transcriptionally. Conclusion: Silibinin is a good sensitizing agent for rhTRAIL-resistant TNBCs.