The carob moth, Ectomyelois ceratoniae is a polyphagus insect pest worldwide. In Iran it is the key pest of pomegranate and alternates to conventional insecticides are being developed. The essential oil of Ferula assafoetida was tested in four pomegranate orchards. In each garden 10 trees were treated with three concentrations of oil. The number of rotten fruits/tree that fell to the ground were counted and removed every 2 weeks during the season. Furthermore, the percentage of rotten fruits/ tree at the harvest time was calculated. All three concentrations of the essential oil significantly reduced fruit infestation by carob moth (P<0.001). However, the 1:1 dose of the oil caused fruits to be scorched. The reduction in infestation may be due to: (i) a direct repellent effect of the oil on the adult carob moth, or (ii) a disruption of mating by volatile compounds emitted by the essential oil.