Human beings use plants for the purpose of disease control and prevention. Maytenus gracilipesrncelastraciae is a plant having vital traditional medicinal values for treating several humanrnailments such as for headache, epilepsy, allergic, peptic ulcer, cancer and immflamations. Thernpresent study was carried out to evaluate the acute and subchronic toxic effects of aqueous leavesrnextracts of maytenus gracilipes celastraciae (kombolcha) on some blood parameters andrnhistopathology of liver and kidney in mice. LD50 was determined.rnThe thesis was carried out in Addis Abeba University, College of Health Science, School ofrnMedicine, Department of Anatomy (Histology Laboratory).The study was conducted from May,rn2014 -July, 2015.The aqueous leaves extracts of M.gracilipes were employed in swiss albinornmice in single oral dose for acute study and repeated oral dose for subchronic study.rnThe LD50, of aqueous extracts of Maytenus gracilipes was found to be 10,000 mg/kg bodyrnweight. In the Subchronic study, the extract was administered orally at doses of 700 andrn2100 mg/kg/day for 90 days . Body weight, biochemical and hematological parametersrnwere determined at the end of the 90 days of daily extract administration.rnIn sub chronic toxicity study daily oral administration of aqueous extract at 700 and 2100 mg/kgrnbody weight/day did not resultrnin death or significantrnchangesrnin body weight,rnhematological and biochemical parameters. Studies on Histopathological examination ofrnselected organs (liver and kidney) showed normal architecture suggesting absence ofrnmorphological disturbances.rnHowever, at 700 mg/kg body weight liver showed pyknotic nuclei and at 2100mg/kg somerncellular infiltrates near the central vein and portal region, where as, in kidney peritubularrninfiltration and focal mono nuclear leukocytic infiltration was observed at higher dose.rnKey words: Maytenus gracilipes, Aqueous extract, acute toxicity, subchronic toxicity,rnHistopathological studies.