Diabetes mellitus is one of the most common non-communicable disorder in the world. It occursrnas a result of either the pancreas not producing enough insulin or the cells of the body notrnresponding properly to the insulin which is produced. Management of diabetes mellitus withrncurrently available modern medicines is costly and chances of side effects are high. These calls forrninvestigations of new and better compounds with least side effects. The experimental plant, Rubusrnerlangeri is among Rubus species, which are used for management of diabetes mellitus in manyrncountries but its effect is not yet experimentally validated. Therefore, the aim of the present studyrnwas to investigate the antidiabetic effects of this plant both in vitro and in vivo and find out thernrelevance of the plant in controlling blood sugar. The in vitro study was assessed using a 3, 5Dinitrosalicylicrnrnacid method for Î±-amylase inhibition activity and DPPH assay method forrnantioxidant activity. The in vivo study on the other hand was carried out in normoglycemic, glucosernloaded hyperglycemic and streptozotocin (200 mg/kg) induced diabetic mice. Blood glucose levelrnwas then determined using glucometer. In all in vivo models, the test groups received various (100,rn200 and 400 mg/kg) doses of the Rubus erlangeri aqueous leaf extract whereas the positiverncontrols received glibenclamide (5 mg/kg) and the negative control as well as the normal controlrngroups received distilled water (10 mL/Kg). The in vitro results demonstrated that this plant hasrnan IC50 of 7.34Â±0.02 Âµg/ml for DPPH scavenging activity and 4.90Â±0.44 Âµg/ml in Î±-amylaserninhibition activity. In both cases, Rubus erlangeri showed comparable effect with the standardrndrugs (ascorbic acid and acarbose). In the in vivo study, the extract significantly reduced bloodrnglucose level with 100 mg/kg at 60 min (p