Medicinal plants in general and essential oils in particular have been recognized as an important natural source of biopesticides. In addition, the effectiveness of these essential oil formulations comes down to the chemical composition which is dominated by a major compound or compounds which presents an interesting prospect and an alternative way of chemical products. The results of this short communication present some works of the value of the essential oil of cedar sawdust (EOCS) as a bioinsecticide for attacks of biotic origin during storage of cereals. The essential oil was obtained by extraction from the Clevenger apparatus. The major constituents in this oil were detected using gas chromatography coupled mass spectrometry and their insecticidal tests was try against adults of three species: Sitophilus granarius, Rhyzopertha dominica and Trogoderma granarium.