Talinum triangulare leaf flavonoid extract (TTFE) was evaluated for its effects on streptozotocin‐hyperglycemia and associated complications especially as it relates to dyslipidemia, lipid peroxidation, and renal dysfunction in rats. Two normoglycemic rat groups designated: control (administered distilled water) and control + TTFE (administered 10 mg/kg b.w. TTFE) and two streptozotocin‐induced (STZ) diabetic rat groups designated: STZ‐control (administered distilled water) and STZ + TTFE (administered 10 mg/kg TTFE). The treatment was given orally once daily for 21 consecutive days. Body weight and insulin concentration showed significant improvement while blood glucose, uric acid, creatinine, and total bilirubin concentrations were significantly reduced in diabetic rats administered TTFE compared to diabetic untreated rats. Furthermore, triglycerides, total cholesterol, LDL‐cholesterol, and malondialdehyde concentrations were significantly lowered in diabetic rats administered TTFE compared with diabetic untreated rats. Key enzymes involved in carbohydrate breakdown and cholesterol synthesis, α‐amylase and 3‐hydroxy‐3‐methylglutaryl‐CoA (HMG‐CoA) reductase, respectively, were significantly inhibited in TTFE‐treated diabetic rats compared to diabetic control. Results presented in this study suggest that administration of TTFE for 21 days normalized STZ‐induced hyperglycemia and its associated dyslipidemia by a mechanism involving inhibition of α‐amylase and HMG‐CoA reductase activities, respectively, in rats.