The immense and ever-growing amounts of agricultural waste have come to be a main concern throughout the world. Therefore, approaches for their processing and value-added reusing are required to enable a sustainable utilization of feedstocks and decrease the environmental burden. In the current study, an essential oil extracted from the husk of Arabic coffee(Coffea arabica) was analyzed chemically using gas chromatography-mass spectrometry (GC-MS) and its constituents were screened for insecticidal activity against the fourth larval instars of the cotton leafworm Spodoptera littoralis (Boisdural). The GC/MS analysis revealed that the arabic coffee included 13 compounds of which Oleic acid comprises the largest proportion 65 % which is known for its insecticidal efficacy. Other compounds that have insecticidal activities were also separated; Cyclononasiloxane, octadecamethyl-, n-Hexadecanoic acid, 9,12-Octadecadienoic acid (Z, Z)- and N-Isobutyl-11-(3,4-methylenedioxyphenyl)-2E,4E,10E-undecatrienoic amide. The oil extract was tested against the 4^th larval instars. The results indicated the efficacy of the extract as larvicide with the values of LC₅₀ and LC₉₀ equal to 1.8083 and 8.3227 respectively. The application of the oil extract against the larvae resulted in the prolongation of both larval and pupal duration and the decrease of the growth rate, pupation, adult longevity and fecundity. Also, the corrected weight of consumed leaf, consumption index (IC), relative growth rate (RGR), the efficacy of ingested and digested food conversion to body tissue (ECI) and (ECD), respectively and the approximate digestibility (AD) were decreased after the application of the oil extract on the larvae. As a result of the current study, the oil extract from the husk of Coffea arabica revealed its efficacy as both larvicide and deterrent against the 4^th instar larvae of cotton leafworm S. littoralis.