The cowpea seed beetle Callosobruchus maculates (Fab.) (Coleoptera: Bruchidae) is considered one of the most important pests attacking various cowpeas species in stores, causing serious damage and great loss of the crop. The present study aimed to evaluate the efficiency of the orange oil against the adults of this pest under laboratory conditions. Experiments were carried out using four concentrations of orange oil (5, 2.5, 1.25 and 0.12 mg/l).The obtained results showed that, the tested concentrations were highly effective against the adults cowpea seed beetle, and there is a positive relationship between the concentration of the oil and the percentage of mortality of the adults. Data show very high mortality rates at all concentrations after 6 days from treatment. The mortality percentage reached 50% and 80% after 3 and 6 days from treatment, at the highest concentration (5mg /L.), respectively.