Seven essential oil samples of two endemic species of Malagasy sage,Salvia sessilifoliaBaker andSalvia leucodermisBaker, were investigated via GC(RI), GC-MS and13C NMR spectrometry. In total, 81compounds were identified accounting for 93.5% to 98.7% of the total composition. The main constituents for the both species were (E)-β-caryophyllene (29.2% to 60.1%), myrcene (1.2% to 21.7%), α-humulene (5.2% to 19.7%), (E)-nerolidol (0.8% to 15.5%) and caryophyllene oxide (1.4% to 10.8%). Ethnobotanical survey of 46 informants revealed that decoctions of leafy twigs and chewed leaves were usually used. Due to the repeated fires, over-harvesting and grazing, the populations ofS. sessilifoliaandS. leucodermisare drastically fragmented. These risk factors led to threats to the habitats of the target species.Salvia sessilifoliaBaker andSalvia leucodermisBaker are proposed to be classified as endangered species.