| Summary: | Essential oils have emerged as viable alternatives to synthetic insecticides for control of mosquito-borne pathogens. The leaf essential oils of eight species of <i>Premna</i> (Lamiaceae) growing in central Vietnam have been obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry. Sesquiterpene hydrocarbons dominated most of the <i>Premna</i> essential oils, with the notable exception of <i>Premna</i><i>mekongensis</i> from Ngoc Linh Nature Reserve, which had α-pinene as the major component. Larvicidal activities against <i>Aedes aegypti</i> have been determined and all of the <i>Premna</i> essential oils showed larvicidal activity with 24-h LC<sub>50</sub> < 65 μg/mL. The leaf essential oils of <i>Premna</i><i>cambodiana</i> from Chu Mom Ray National Park and <i>Premna</i><i>mekongensis</i> from Ngoc Linh Nature Reserve showed the best larvicidal activities with 24-h LC<sub>50</sub> of 16.8 and 18.0 μg/mL, respectively. The essential oil compositions and larvicidal activities of <i>P. cambodiana</i>, <i>Premna flavescens</i>, <i>Premna</i><i>maclurei</i>, <i>P. mekongensis</i>, and <i>Premna</i><i>puberula</i> are reported for the first time. Although the larvicidal activities of <i>Premna</i> leaf essential oils are promising, the essential oil yields are relatively low (0.10–0.25%).
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