Aim: This study aimed to elucidate the effects of grape seed proanthocyanidin extract (GSPE) on oxidative stress (OS), antioxidant enzymes, free radicals and cytokines in the pancreas of T1DM rats. Methods: Two-month-old Wistar rats were assigned to the control (CON), CON + GSPE (CON + PA), diabetics (STZ, 60 mg/kg b.w.), diabetes + GSPE (STZ + PA), diabetes + insulin (STZ + INS, 3 U/day) and diabetics + GSPE and INS (STZ + INS + PA) groups. GSPE (75 mg/kg b.w.) was administered daily either alone or with INS for 8 weeks. Results: Glutathione was lowest in diabetics while it increased in the STZ + INS + PA (p <.001) group, similar to catalase activity (p <.05). Hydrogen peroxide, superoxide and lipid peroxidation increased with iNOS, TNF-α and IL-1β in the diabetic pancreases, while GSPE decreased (p <.001). Further, reduced β-cells/islet number was improved in diabetics (p <.001) with treatment. Conclusion: This study suggests that GSPE with INS is effective in minimising OS and pancreatic degeneration in T1DM rats. © 2021 Informa UK Limited, trading as Taylor & Francis Group.