The study investigates the potential antidiabetic, renoprotective, and cardioprotective effects of coriander seed extract (CSE) and garlic extract (GE) in streptozotocin (STZ)-induced diabetic rats. Thirty adult male rats were divided into five groups: a control group, a diabetic untreated group, and diabetic groups treated with glibenclamide, CSE and GE. Treatment continued daily for 28 days. Serum biochemical studies showed that diabetic rats had significantly higher levels of glucose, creatinine, urea, uric acid, Creatine Kinase-MB (CK-MB) and Lactic Dehydrogenase (LDH) levels than the control group. Histopathological and immunohistochemical examinations revealed marked hypocellularity, degeneration, and necrosis of pancreatic islets, accompanied by a significant reduction in insulin expression in comparison with the control. Additionally, diabetic rats exhibited structural damage in the kidneys and heart, characterized by tubular epithelial degeneration and necrosis and myocardial myomalacia. Administration of CSE and GE significantly mitigated these biochemical and histological changes, with CSE demonstrating superior protective effects. These results highlight the therapeutic potential of CSE and GE particularly emphasizing CSE as an effective natural therapy for managing diabetes and its associated renal and cardiac complications.