Methanolic extract of bioactive compounds of Eucalyptus citriodora was assayed for in vitro anti-insect activity against Tribolium castaneum (Herbst). GC-MS analysis of Eucalyptus citriodora revealed the existence of the ?-Pinene , Eucalyptol , 2,4-Dimethylstyrene , Isopinocarveol , Cis-p- menthe-1(7),8-dien-2-ol , Bicyclo[3.1.1] heptan-3-ol,6,6-dimethyl-2-methylene-,[1S-(1? , 5-Caranol,(1S,3R,5S,6R)-(-)- , Terpinen-4-ol , Thymol , ?-Terpineol , 7-epi-trans-sesquisabinene hydrate , ?-Elemene , ?-copaene , Azulene ,1,2,3,3a,4,5,6,7-octahydro-1,4-dimethyl-7-(1-methyl) , Alloaromadendrene , ?-Guaiene , Epiglobulol , Globulol, 2-Naphthalenemethanol , decahydro-?,?, 4a-trimethyl-8-methyl , 8-epi-gama-eudesmol , ?-acorenol , Perhydrocyclopropa[e]azulene-4,5,6-triol , 1,1,4,6-tetramethyl , Phenylalanine , 4-amino-N-t-butyloxycarbonyl-,t-butyl ester , 1,4-Naphthoquinone , 6-acetyl-2,5,7-trihydroxy- , 1-Glyceryl ricinoleate , Decanedioic acid , dibutyl ester , Curan-17-oic acid ,2,16-didehydro-19-hydroxy-,methyl ester, 1,4-Naphthoquinone , 2-acetyl-5,8-dihydroxy-3-methoxy- , 9-Octadecenamide , (Z)- , 9-Octadecenamide, 12-hydroxy-,[R-(Z)]- , Tertbutyloxyformamide , N-methyl-N-[4-(1-pyrrolidinyl)-2-butynyl, 17-Pentatriacontene, Vitamin E and ?-Sitosterol. The FTIR analysis of Eucalyptus citriodora leaves proved the presence of Alkenes, alkyl halides and alkanes. Eucalyptus citriodora was highly active on accumulative mortality of Tribolium castaneum (Herbst) (adult).