The present work aimed to studying the effect and evaluate the effectiveness of the clove oil as a natural product against the adults of the cowpea seed weevil, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) under controlled laboratory conditions. The study was carried out at the Biology Department, Faculty of Science, Princes Nora University, Al Riyadh, Saudi Arabia, using four concentrations of clove oil (5, 2.5, 1.25 and 0.12 mg/L). Results obtained indicated that, the mortality percentage of the adult beetles increased with the increase of the oil concentration and the period after treatment. The percentage of mortality was 63.333% two days after treatment at the highest concentration (5mg/L), increased to reach 96.667% four days after treatment at the same concentration. At the lowest concentration (0.12 mg/L), the percentage of mortality was 73.333% four days after treatment and the LC₅₀ value was 2.188 mg/l and the LC₉₀ was 75.445 mg/l after two days from treatment.