Malaria is a major public health problem caused by parasites, namely, Plasmodium vivax, P. falciparum, P. ovale and P. malariae transmitted via the bites of the female anopheles mosquito. The illness results in recurrent attacks of chills and fever and is characterized by high morbidity and mortality rates. G.macrophyllus is used traditionally to treat fever. On the basis of this, the extracts of G.macrophyllus are evaluated for its antimalarial activity with the β-hematin inhibition assay. During intra erythroctic growth and proliferation, hemoglobin is utilized as a major source of nutrition by the malaria parasite and haem (ferriprotoporphyrin IX) is released as a toxic byproduct. The major route of haem detoxification in the malaria parasite is through the formation of haemozoin or β-haematin. Thus, inhibition of the β-haematin is utilized as an antimalarial drug target. The ground dried roots of Goniothalamus macrophyllus were extracted in aqueous methanol and the crude extract was sequentially partitioned with n-hexane, chloroform and butanol. The crude methanol, hexane, chloroform, butanol and residual were assayed for β-haematin inhibition. The inhibitory activity was determined by colorimetric method, measured at 405 nm with a microplate reader. Choloroquine, the most widely used antimalarial drug was used as the positive control. Based on the β-haematin inhibiton assay, butanol extract exhibited an IC50 value of 32 ± 0.06 μg/ml and was most potent towards the inhibition of β-hematin compared to the other extracts.