To identify the insecticidal components of Terminalia arjuna bark were evaluated by standard protocol using the equipment Perkin-Elmer Gas Chromatography–Mass Spectrometry. The mass spectrum of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST) library. The GC-MS analysis revealed the presence of various compounds like Phenol, 4H-Pyran-4-one, 2, 3-dihydro-3, 5-dihydroxy-6-methyl, 2-Methoxy-4-vinylphenol, Benzaldehyde Methoxy, Dodecanoic acid, Tetradecanoic acid, Hexadecanoic acid, methyl ester, n-Hexadecanoic acid and Octadecanoic acid, 4-Hydroxy-3 present in the extract. Among the various compounds, Phenol, 4H-Pyran-4-one, Tetradecanoic acid, Hexadecanoic acid, methyl ester, n-Hexadecanoic acid and Octadecanoic acid identified as insecticidal activity using NIST library. These findings support the use of Terminalia arjuna as insecticidal plant.