Nepata cateria (Labiatae) growing widely in northern Nigeria is used by most indigenes for the treatment of malaria and other related diseases. The in vivo anti-malarial activity of the methanol leaf extract was evaluated in mice infected with the chloroquine sensitive Plasmodium berghei berghei NK65 strain. Oral acute toxicity of the methanol leaf extract with modified Lorke`s method was evaluated against early, established, curative, prophylactic, and residual infections and their mean survival period studied. The oral median lethal dose of the extract in mice was determined to be about 3800 mg kg -1 body weight. The extract at doses of 100, 200 and 400 mg kg -1 body weight produced significant (P < 0.05) dose dependent activity against the parasites in the suppressive, curative and prophylactic tests. The results suggested that the methanol leaf fraction of N. cateria possesses antimalarial activity and thus lends credence to its ethno medical and folkloric usage as malaria cure.