Vascular diseases are the most important diabetic complications. Its pathophysiology involves abnormalities in vascular endothelium caused by sustained hyperglycemia, increased uric acid, increased oxidative stress, and inflammation mediated through toll-like receptor 4 (TLR 4) pathway. Hibiscus sabdariffa has been used traditionally in food products and it possesses anti-diabetic, anti-hyperlipidemic, anti-oxidative, anti-inflammatory, and anti-hypertensive effects. The present study aimed to investigate the effect of hibiscus extract against diabetic vascular complications. Diabetes was induced by a single injection of streptozotocin (STZ, 55 mg/kg, i.p.). Diabetic rats were treated with hibiscus extract (100, 200, or 400 mg/kg), lisinopril (5 mg/kg), or lisinopril plus hibiscus (2.5/100 mg/kg) daily for 8 weeks. Hibiscus extract significantly and dose-dependently improved abnormalities in serum lipids and blood pressure. Additionally, it suppressed oxidative stress, inflammation, particularly the upregulation of TLR 4 induced by STZ. There were no significant differences between the effects of hibiscus (400 mg/kg) and lisinopril (5 mg/kg). The effects of the combined administration of lisinopril plus hibiscus (2.5/100 mg/kg) were significantly better compared with either lisinopril or hibiscus alone. These results suggest the use of hibiscus as an alternative to the conventional use of angiotensin-converting enzyme inhibitors (ACEIs) or at least in combination with a small dose to enhance their effects in diabetic vascular complications.