Peritoneal carcinomatosis is a frequent and often fatal condition for patients and its diagnosis usually occurs when the tumor growth is too spread and hence uncontrollable by current treatments. To evaluate new therapeutic avenues, we have evaluated adoptive T cell therapy in B16.OVA and Panc02.OVA tumor models disseminated in the peritoneum using tumor-specific T cells armored with mRNAs encoding the IL-12 or the IL-33 cytokines. IL-12 mRNA-engineered OT-I therapy was administered either intraperitoneally or intravenously. Locoregional injection promoted T cell homing to tumor-bearing omentum, induced primary tumor eradication, development of endogenous antigen-specific immunity, the positive reprogramming of tumor immune microenvironment and a longer persistence of transplanted T cells in vivo. IL-12 can be defined as a promising therapy in terms of anti-tumor efficacy in the treatment of peritoneal carcinomatosis. IL-33 is an alarmin cytokine released upon cell damage and is involved in tissue homeostasis and repair, type 2 immunity, allergic and non-allergic inflammation and it has been shown to have a dual role in the cancer setting.  Locoregional delivery of IL-33-mRNA armored OT-I T cells rescued 50% of the mice from peritoneal carcinomatosis development in both tumor models and conferred long-lasting anti-tumor immunity upon subcutaneous re-challenge with the parental cell line.  Considering the promising results, we believe that IL-33 may be an interesting option to widen the immunotherapeutic tools against peritoneal carcinomatosis.