Objective: To determine the mosquito larvicidal activity of leaf essential oil and their chemical constituents from Clausena anisata (Willd.) Hook. f. ex Benth. against Anopheles subpictus and Aedes albopictus. In addition, the chemical composition of the leaf essential oil was analyzed using gas chromatography–mass spectrometry. Methods: Twenty late III instar larvae of two mosquito species were exposed to based on the wide range and narrow range tests, essential oil was tested at 50, 100, 150, 200 and 250 ppm and each compound was tested at various concentration (5-75 ppm) and were assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC50 values of the Clausena anisata leaf essential oil and their major compounds were determined by Probit analysis. Results: The oil contained mainly β-pinene (32.8%), sabinene (28.3%), germacrene-D (12.7%), estragole (6.4%) and linalool (5.9%). The essential oil from the leaves of Clausena anisata exhibited signiﬁcant larvicidal activity, with 24 h LC50 values of 122.57and 134.08 ppm, respectively. The five pure constituents extracted from the Clausena anisata leaf essential oil were also tested individually against two mosquito larvae. The LC50 values of β-pinene , sabinene , germacrene-D, estragole and linalool appeared to be most effective against Anopheles subpictus (LC50 – 24.68, 20.93, 17.16, 12.25, 36.26 ppm) followed by Aedes albopictus (LC50 – 28.10, 22.66, 19.51, 13.01, 39.99ppm). Conclusions:The present findings suggest that the leaf essential oil of Clausena anisata and its five major compounds might be considered as a potent source for the production of natural larvicides.