Objective: Mesenchymal stem cells (MSCs) are also promising in immunosuppressed patients after organ and tissue transplantation, in addition to their current wide range of uses and research areas. Sunitinib is a receptor tyrosine kinase with immunosuppressive properties and its cytotoxic activity in different types of cells is known. Our study aimed to elucidate the effect of oxytocin on sunitinib-treated MSCs. Methods: For this purpose, commercially available rat adipose tissue-derived MSC (ADMSCs) was used. The individual or combinational effect of the active substances on viability was evaluated with WST-1, the effect on apoptosis Annexin V, the effect on oxidative stress markers MDA, CAT, GPX, and SOD ELISA tests. Results: The IC50 value of sunitinib was determined as 44.57 μM at the 48th hour, and it was determined that oxytocin had no cytotoxic effect in doses up to 100 μM. Treatment of the two agents in combination increased the cytotoxic effect of sunitinib. Oxytocin attenuated the effect of sunitinib on apoptosis and lipid peroxidation. Conclusion: It is important to investigate the efficacy of these two substances individually and in combination with ADMSCs with further experiments to evaluate the potential use of oxytocin in organ and tissue transplantations.