BACKGROUND: 5-fluorouracil (5-FU) is a broad-spectrum drug that has a wide range of side effects. Patients may experience severe comorbidities as a result of these toxic side effects, making it impossible for them to continue chemotherapy. Despite the fact that various molecules have been experimented, there is no literature data on the efficacy of dexpanthenol (DXP) for mitigating the toxic effects of 5-FU. OBJECTIVE: To investigate the protective effects of DXP on nephrotoxicity, hepatotoxicity, and intestinal toxicity induced by 5-FU in rats. METHODS: Twenty-eight male Wistar-Albino rats aged 16 weeks were randomly assigned to four groups. We created a rat model of intestinal mucositis, nephrotoxicity, and hepatotoxicity through intraperitoneal 5-FU (35 mg/kg for 4 d) injection. 500 mg/kg and 1000 mg/kg of DXP were administered to the treatment groups. The effects of dexpanthenol were evaluated clinically, biochemically, histopathologically, and immunohistochemically (inducible nitric oxide synthase [iNOS], cyclooxygenase-2 [COX-2], 8-hydroxyguanosine [8-OHdG], and nuclear factor kappa B [NF-κB]). RESULTS: 5-FU caused a decrease in body weight and food intake, and an increase in diarrhea scores in rats. 5-FU led to significant disruptions in the hepatic biochemical markers (aspartate transaminase [AST], alanine transaminase [ALT], alkaline phosphatase [ALP], total bilirubin, direct bilirubin, and lactate dehydrogenase [LDH]), renal biochemical markers (blood urea nitrogen [BUN], creatinine, and uric acid), and protein and albumin, which are markers of both hepatic and renal functions. Severe pyknosis and mononuclear cell infiltrations were observed in the liver, and mononuclear cell infiltration and tubular degeneration in the kidneys. Jejunum and colon showed villous hyperemia and hemorrhage, respectively, along with mononuclear cell infiltration. Furthermore, 5-FU increased the immunohistochemical expressions of iNOS, COX-2, 8-OHdG, and NF-κB in the examined tissues. The administration of DXP at doses of 500 mg/kg and 1000 mg/kg demonstrated significant mitigation of the toxic effects induced by 5-FU on the liver, kidney, jejunum, and colon. CONCLUSION: DXP showed protective effects against nephrotoxicity, hepatotoxicity, and intestinal toxicity caused by 5-FU. These findings suggest that DXP may serve as a potential therapeutic agent to alleviate the severe side effects of 5-FU chemotherapy, thereby improving patient tolerance and quality of life. Further clinical studies are warranted to validate these results and explore the translational potential of DXP in human cancer therapy.