During the screening of antimalarial substances, MeOH extract from the twigs of Ficus septica was shown to have potent antimalarial activity. Bioassay-guided fractionation of a methanol extract of the twigs of F. septica led to the isolation of a new seco-phenanthroindolizine alkaloid and three known phenanthroindolizine alkaloids. Their structures were elucidated on the basis of NMR analysis. All isolated compounds were tested against Plasmodium falciparum. Compounds 2-4 displayed antimalarial activity against the 3D7 strain of P. falciparum with IC50 values 0.028-0.42 µM, whereas a new compound 1 exhibited a moderate antimalarial activity.