Background/Aim. Irreversible electroporation (IRE) showed promising results for small-size tumors and very early cancers. However, further development is needed to evolve this procedure into a more efficient ablation technique for long-term control of tumor growth. In this work, we show that it is possible to increase the antitumor efficiency of IRE by simmultaneously injecting c-di-GMP, a STING agonist, intratumorally. Materials and Methods. Intratumoral administration of c-di-GMP simultaneously to IRE was evaluated in murine models of melanona (B16.OVA) and hepatocellular carcinoma (PM299L). Results. The combined therapy increased the number of tumor-infiltrating IFN-γ/TNF-α-producing CD4 and CD8 T cells and delayed tumor growth, as compared to the effect observed in groups treated with c-di-GMP or IRE alone. Conclusion. These results can lead to the development of a new therapeutic strategy for the treatment of cancer patients refractory to other therapies.