Abstract Repeated pancreatic insults and inflammation can lead to the development of pancreatitis. In this study, the therapeutic potential of a nano-formulated metformin drug with chitosan (Cs-Met NPs) and/or low doses of γ-irradiation (IR) was evaluated against acute pancreatitis (AP) induced by L-arginine in an animal model. Thirty adult Wistar rats were randomly divided into five groups: normal control, L-argininetreated (AP), AP+IR, AP+Cs-Met NPs, and AP+IR+Cs-Met NPs. Histopathological examination of the pancreas was performed, and biochemical parameters including serum amylase and lipase levels, random blood glucose (RBS), plasma insulin levels, insulin-like growth factor 1 (IGF-1), tumor necrosis factor-alpha (TNF-α), interleukins (IL-6, IL-8, IL-10), and C-reactive protein (CRP) were measured. L-arginine treatment significantly elevated serum amylase and lipase levels, as well as IL-6, IL-8, TNF-α, RBS, and CRP levels. It also substantially decreased IL-10, insulin, and IGF-1 levels. Microscopic examination revealed loss of pancreatic lobular architecture, marked fibrosis, acinar cell degeneration, inflammation, and edema. Administration of CsMet NPs and/or low-dose γ-irradiation markedly improved both the biochemical parameters and histopathological features. Conclusion: Nano-formulated metformin and/or low-dose γ-irradiation demonstrated significant therapeutic effects in a rat model of L-arginine-induced acute pancreatitis. Keywords Acute pancreatitis, Metformin nanoparticles, Gamma irradiation, Low-dose radiation, Inflammatory cytokine