Two new antiplasmodial peptides, named koshidacins A (<b>1</b>) and B (<b>2</b>), were discovered from the culture broth of the Okinawan fungus <i>Pochonia boninensis</i> FKR-0564. Their structures, including absolute configurations, were elucidated by a combination of spectroscopic methods and chemical derivatization. Both compounds showed moderate <i>in vitro</i> antiplasmodial activity against <i>Plasmodium falciparum</i> strains, with IC<sub>50</sub> values ranging from 17.1 to 0.83 μM. In addition, compound <b>2</b> suppressed 41% of malaria parasites <i>in vivo</i> when administered intraperitoneally at a dose of 30 mg/kg/day for 4 days.