The essential oil of Cymbopogon martinii was tested for its potency as botanical pesticide in protection of stored wheat and gram samples from insect infestation. The C. martinii oil exhibited its potency as botanical fumigant in protection of the stored gram. The oil showed prominent repellent behaviour against Callosobruchus chinensis and Tribolium castaneum. Geraniol, the major component of the oil, was not as efficacious as the Cymbopogon oil in protection of insect infestation of stored wheat and gram. C. martinii oil significantly affected oviposition and adult development as well as mortality of C. chinensis in cow pea. The Cymbopogon oil when used as fumigant did not affect viability, germination and seedling growth of gram. Because of insecticidal as well as semiochemical nature, the oil as such may be recommended in the integrated pest management program in protection of stored food commodities as an alternative to the synthetic pesticides.