Introduction: The use of oncolytic viruses are significant approach to cancer therapy. themechanisms of oncolytic viruses are vary in different type of cancers due to cellular pathways intumoral cells. Reoviruses as an instance of oncolytic virus can be therapeutic agent in colorectalcancer. Since the novel mechanisms such as mesemchymal stem cells (MSCs)-derived secretomeare recently attracted the attention to cure cancers, we decided to combine these two way forthreatment of colorectal cancer.Materials and Methods: Female BALB/c mouse (6-8 weeks old) was obtained from PastureInstitute of Iran. MSCs were isolated from abdominal adipose tissue and cultured under standardsituation in 37ᵒcand 5% CO2. MSCs were confirmed by antibody CD markers as CD45, CD29,CD90 and CD105 with flow cytometry method. All secretome over the cell cultures was collectedand filtered by 0.2 μm filter to use for following steps. CT26 as colorectal cancer model andcontrol cells such as L929 were cultured in six-well plate and confronted with MSC-derivedsecretome and Reovirus (MOI=1).Results: Therapeutic effect of MSCs-derived secretome along with oncolytic Reovirus is increasedafter 72 hours by observation of cytopathic effects in CT26 and also in control cells.Conclusion: In the current study, we have demonstrated that the proliferation and growth of CT26and L929 were decreased in confront with Reovirus and secretome in comparison of secretomewithout Reovirus.