Toxicological studies are sources of useful information for evaluating the therapeuticrnbenefits of locally used medicinal plants. Vernonia bipontini (V. bipontini) is a herb usedrnfor treatment of malaria and malaria related symptoms in Ethiopia. However, its siderneffects have not been studied. In this study, the toxic effects of aqueous and methanolicrnextracts of V. bipontini leaves on some blood parameters and on liver and kidney, tissuesrnin mice were investigated.rnLethal doses at which 50% of experimental mice died (LD50s) in both aqueous andrnmethanolic leaf extracts of V. bipontini were determined by administering different dosesrn(1250-3250mg/kg for aqueous leaf extract and 1250-2750mg/kg for methanolic leafrnextract) to experimental animals using intragastric catheter. For long-term toxicity study,rnsixty male and female Swiss albino mice were equally divided into six groups of 10rnanimals each. Groups1 and 2 were set as the control and received 0.5ml of distilled waterrnand 0.5ml of 4% tween in distilled water, respectively, at 24 hrs intervals for 45 days.rnGroup 3 and 4 were subjected to oral administration of the aqueous leaf extract at 400rnand 800mg/kg, respectively, while group 5 and 6 were treated at 400 and 800mg/kg ofrnmethanolic leaf extract, respectively in 24 hrs intervals for 45 days. All groups werernclosely observed for any physical and behavioral alterations. Body weights of the micernwere recorded on the first day and the last day of administration. Each animal wasrnsacrified under diethyl ether anesthesia on the 46th day. Following sacrifice, blood samplernwas collected by cardiac puncture using sterile needle and 5ml syringe into heparinizedrntest tubes for hematological studies and into non-heparinized tubes for biochemicalrnanalysis. Hematological parameters (total RBC, WBC, platelets, lymphocytes, Hgb, Hct,rnMcv, Mch, and Mchc) and biochemical parameters (AST, ALT, ALP, and urea) werernevaluated. Through a vertical, midline incision, the liver and kidney of each animal werernremoved and cleaned of the surrounding tissues. Each sample was fixed in 10% bufferedrnformalin overnight. The tissues were processed for light microscopy.rnThe LD50s of the aqueous and methanolic leaf extracts of V. bipontini were 2500.62Â±5.24rnmg/kg and 2130.6Â±1.5mg/kg, respectively. No deaths were recorded among the controlrngroups. The aqueous leaf extract has no significant (P>0.05) effect on liver and kidneyrnweights, and hematological and biochemical parameters at all doses when compared withrncontrol group. Treatment with 800mg/kg body weight of methanolic leaf extractrnsignificantly (P