The toxic effect of Abrus precatorius seeds powder against the wheat weevil Sitophilus granarius adults over a period of 14 days was studied. Data confirmed that, at all concentrations, the mortality percentage increased as the exposure period was prolonged and also as the applied concentration was increased. Seven days post-treatment the LC₅₀ value was 0.12% (w/w). The correspondent value at 14 days was significantly decreased being 0.05% (w/w). Hence, A. precatorius seeds powder was toxic against S. granarius. The powder proved, also, that it had a repellent effect against the tested insect. The phytochemical investigation of A. precatorius seeds illustrated that it was rich in tannins, saponins and phenols. The LC₅₀ and two higher concentrations of A. precatorius powder seeds were evaluated, also, against thirty-six adult males of Rattus rattus over a period of 30 days. Rats were randomly assigned to 4 groups 9 rats/ group. Rats of the first group were fed on grains mixed with LC₅₀ (0.12%)of powder. The second group fed on grains mixed with 5% powder. The third group was on grains mixed with 10% powder. While the fourth group was fed on untreated grains as control. Three replicates were used in each group. Blood samples were obtained for haematological and biochemical analysis. Specimens of the liver, kidney, spleen, testis, and stomach were, also, taken for histopathological studies. The whole results showed that the powder of A. precatorius seedshas potential toxicity as shown by the effects it caused on the serum chemistry as well as on the changes noted on the studied organs.