Malaria is a major public health problem in the world in general, and in developingrncountries, in particular. Treatment of cases is becoming difficult which causes a greatrneconomic lose of a country. But it is also difficult to treat malaria due to the increasingrndrug resistance. The in vivo antimalarial activities of the hydroalcholic extracts of twornplants, M. azedarach (leaves, seeds and barks) and H. trif/ora (leaves and root) wasrninvestigated in this study.rnThe mice were infected with Plasmodium berghei intraperitoneally. The in vivornantimalarial activity of the hydroalcholic extracts against Plasmodium berghei wasrnassessed using the 4-day suppressive test procedure. The extracts were administeredrnby oral route daily for four days starting from the day of parasite inoculation.rnThe extracts of both plants had intrinsic antimalarial properties that were dosedependent.rnM. azedarach leaves, seeds and barks extracts suppress the parasitemia byrn42.60%, 35.80% and 35.09% respectively. While the hydroalcholic extracts of H. trif/orarn(leaves and root) showed a suppression of parasitemia by 55.7% and 38.19%rnrespectively. The plant extracts are less potent than the standard drug used in thisrnstudy.rnPreliminary phytochemical screening of M. azedarach (leaves, seeds and barks)rnextracts indicated the presence of alkaloids, phenoliCS, flavonoids, saponins, terpenoidsrnand tannins, while H. trif/ora (leave and root) extract showed the presence of alkaloids,rnphenolics, flavonoids and doubtful amount steroidal compounds and saponins. Thernstudy revealed that the crude extracts obtained from both plants grown in Ethiopia havernthe potential to be used as antimalarial agents, as seen from its suppressive effectsrnagainst P. berghei. Alkaloids are doubtful in the bark extract of M. azedarach.rnA preliminary toxicity study of M. azedarach and H. triflora crude extracts was donernusing Swiss albino mice in oral doses of 1000, 2000, 3000 and 5000 mg/kg of bodyrnweight. The results showed that the medium lethal dose (LD so) of the extracts is higherrnthan 5000 mg/kg body weight and hence, in a single dose administration, the plantrnextracts had no adverse effects.rnKey words: Malaria, Plasmodium falciparum, Plasmodium berghei, Melia azedarach,rnHypostes trtf/ora.