Abstract: Ethyl acetate extract and the purified fraction extracted from ripe fruits of Melia azedarach were tested against the 2nd and 4th instar larvae of Spodoptera littoralis. The extract and the fraction showed high significant toxic activities and reduction in larval weight at all concentrations used. The LC50 values of the extract were 4.10 and 16.04 against the 2nd and 4th instars, respectively, while for the purified fraction were 1.19 and 2.01 against the same instars. The chemical constituents of the purified fraction were identified by LC-MS. Ten components were identified, four of these components were previously isolated and six compounds were identified for first time from fruits of Melia. azedarach. [Melegi A. Abd El-Ghany, Mohamed Farag, Heba Yousef, Mohamed H. M. Ahme، Samy S. El-badawey and Adel A.-H. Abdel-Rahman. Insecticidal Activity of Melia azedarach L. Triterpeniods against Spodoptera littoralis (Boisd.). Journal of American Science 2012; 8(3): 661-667]. (ISSN: 1545-1003). http://www.americanscience.org. 89