The present study aimed to assess the antihyperglycemic effect of Cleome droserifolia (samwa) ethanol extract in alloxan-induced diabetic rats and to shed more light on the phytochemical screening of this plant and the chemical analysis of its ethanol extract. Alloxan-induced diabetic male albino rats were treated with ethanol extract at intragastric dose level of 200 mg/kg body weight for 4 weeks and were compared with the diabetic control rats given the equivalent amount of the vehicle (dimethylsulfoxide, DMSO). Oral glucose tolerance test, liver glycogen and serum insulin were determined. The chemical screening of C. droserifolia (samwa) indicated the presence of glycosides and/or carbohydrates, cardenolides, saponins, sterols and/or triterpenes, tannins, catechins and flavonoids. The treatment of the diabetic rats with samwa ethanol extract exerted marked amelioration of the deteriorated glucose tolerance and the impoverished liver glycogen content without concomitant increase in serum insulin concentration. Moreover, the administration of the extract caused a noticeable increase in the islets cells number with marked amelioration in the islet architecture. Key words: Samwa ethanol extract, phytochemical screening, diabetic rats