Objective: This study evaluated the renoprotective effects of p-Coumaric acid nanoparticles (PCNPs) in nephropathic rats. Methods: Six groups of male Albino Wistar rats were randomly assigned. Group 1 was the control, while Group 2 received 45 mg/kg of streptozotocin (STZ) to induce diabetic nephropathy. Groups 3, 4, and 5 received STZ (45 mg/kg) along with PCNPs at doses of 20, 40, and 80 mg/kg, respectively. Group 6 received 80 mg/kg of PCNPs without STZ. Body weight, blood glucose, insulin, hemoglobin (Hb), and glycosylated hemoglobin (HbA1c) levels were measured. Blood urea, serum creatinine, kidney antioxidant enzymes, and lipid peroxidation levels were also analyzed. Histological and immunohistochemical studies of kidney tissues were performed. Results: PCNPs (80 mg/kg) significantly reduced serum glucose, creatinine, and urea levels while increasing insulin levels and antioxidant activity in the kidneys. Histological analysis revealed that nephropathic rats exhibited cellular damage, including shrinkage of Bowman’s capsule and lesions in the kidneys, along with degeneration in the Islets of Langerhans in the pancreas. PCNPs treatment restored these morphological alterations in the pancreas, liver, and kidneys to near-normal. Furthermore, nephropathic rats had elevated IL-6 and TNF-α expression in the renal tubules and glomeruli, which was reduced following PCNPs treatment. Conclusion: The findings suggest that PCNPs exhibit antihyperglycemic, antioxidant, anti-glycation, and renoprotective effects in STZ-induced diabetic nephropathy. © 2025 Elsevier B.V., All rights reserved.