The present study was undertaken as antihyperlipidaemic effect of an aqueous leaves extract of Solanum trilobatum L. on streptozotocin (STZ)- induced diabetic rats. Repeated administration of the leaves extract of S.trilobatum (100mg and 200mg/kg b.w) for 21 days resulted in significant reduction in serum and tissue triglycerides, cholesterol, free fatty acids and phospholipids in STZ diabetic rats. In addition to that, significant (P<0.05) decrease in high density lipoprotein (HDL) whereas significant increase (P<0.05) in low density lipoprotein (LDL) and very low density lipoprotein (VLDL) were observed in STZ diabetic rats, which were normalized after 21 days of leaves extract treatment. The leaves extract at a dose of 200mg/kg.body wt. showed much significant antihyperlipidaemic effect than at the dose of 100mg/kg-body wt. The study was compared with a standard drug, tolbutamide (100mg/kg b.w).