Insects cause extensive damage to stored grains and their products. Among the stored grain pests Tribolium castaneum (Herbst.) is considered as one of the destructive pests. Since botanical insecticides are less hazardous to humans and the environment, they are frequently recommended for pest management during storage. This study aimed at evaluating the synergistic effect of ethyl acetate extracts of Lantana camara L., and Tithonia diversifolia against T. castaneum (Herbst). The leaves were washed, air dried (27 ± 2 ○C), and powdered before extracting them with ethyl acetate as a solvent. Bio efficacy of individual and combination of extracts were studied through different concentrations (0.2, 0.4, 0.6 μg/μL) against the adult beetles of T. castaneum to assess the contact toxicity and repellency effect. L. camera showed higher mortality and repellency effects over T. diversifolia and the positive control. However, the combination of both plant extracts (CE) significantly enhanced (P < 0.05) the mortality percentage and repellency over the individual crude extracts. Therefore, it can be concluded that the combination of both plant extracts showed synergistic effect on toxicity and repellency against T. castaneum.