Background: Acute pancreatitis (AP) is a globally significant disease with increasing incidence and prevalence especially in the western world. It has severe complications such as pseudocyst, infection, renal failure, breathing problems, diabetes, malnutrition and chronic pancreatitis. Chronic pancreatitis can lead to pancreatic cancer which is one of the worst types of cancer. Up till now, there is no licensed specific treatment for AP. Objective: This study investigated the therapeutic effects of Mito-TEMPO in treatment of L-Arginine induced acute pancreatitis in rats besides a possible involved mechanistic pathway. Materials and methods: Rats randomly allocated into 3 groups: (1) control (received normal saline), (2) L-Arginine treated (300mg/100gm, i.p once) & (3) L-Arginine+Mito-TEMPO treated (0.7mg/kg/ day, i.p for 7 days). After 7 days from AP induction, serum amylase & lipase, pancreatic inflammatory mediators “toll like receptor-4 (TLR-4), nuclear factor kappa-B (NF-кB), NLRP3 inflammasome, caspase-1, interleukin-1 beta (IL-1B)", oxidative parameters “malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NO), reduced glutathione (GSH)", an apoptotic marker “caspase-3" & pancreatic histopathological changes were estimated for all rats. Results: L-Arginine induced AP was evidenced by elevation of serum amylase & lipase, pancreatic inflammatory mediators “TLR-4, NF-кB, NLRP3 inflammasome, caspase-1, IL-1B", oxidative parameters “MDA, MPO, NO", the apoptotic marker “caspase-3" and infiltration of inflammatory cells proved through hematoxylin & eosin stain alongside with reduction of GSH content. All these harmful effects were improved significantly after administration of Mito-TEMPO. Conclusion: Mito-TEMPO can be introduced as a new therapy for the treatment of acute pancreatitis due to its anti-inflammatory and anti-oxidant effects.