Trypanocidal constituents of Pogostemon cablin were investigated. Activity guided isolation of the acetone extract resulted in isolation of three new sesquiterpene hydroperoxides 1-3, together with a known sesquiterpene, patchouli alcohol (4). In vitro minimum lethal concentrations of the hydroperoxides 1-3 against epimastigotes of Trypanosoma cruzi were 0.84 microM (1), 1.7 microM (2) and 1.7 microM (3). The activity of the corresponding alcohols and patchouli alcohol was very weak (MLC>200 microM).