The structure of two compounds extracted from the leaves of Vitex negundo L., their repellent activity and toxicity against three strains of Tribolium castaneum (Herbst) were elucidated. Two compounds were purified and a residual film bioassay was used to evaluate the toxicity to adult T. castaneum. Mortality was recorded 24, 48 and 72 h post-exposure to compounds. The repellency activity of methanol extract was tested by using nine concentrations. Each dose was applied on a half circle of the filter paper, keeping the other part untreated. Insects released on treated filter paper were assessed for repellency up to 5 h. Two bioactive compounds, 22,23-dihydro-α-spinasterol-β-d-glucoside and salicylic acid were isolated from the methanolic leaf extracts by column chromatography and thin-layer chromatography. Their structures were elucidated by various spectroscopic methods. Compound 22,23-dihydro-α-spinasterol-β-d-glucoside is the first report from this plant. Both compounds showed insecticidal activity and the leaf extracts caused 100% repellency in the three tested strains of T. castaneum. Both compounds showed toxicity to T. castaneum, but compound 22,23-dihydro-α-spinasterol-β-d-glucoside was more potent. Its potential future use as herbal insecticide against T. castaneum is discussed.