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Laboratory experiments were conducted at the Federal University of Technology, Owerri, southeastern Nigeria to evaluate the efficacy of the seed and root extracts of Jatropha curcas L. with a known synthetic insecticide and its residual toxicity in controlling Callosobruchus. maculatus (F.) on stored cowpea seeds. The experiments were laid out in a Completely Randomized Design. The treatment materials consisted of root and seed extracts of J. curcas tested at 0.00, 1.00, 2.00 and 3.00 ml/ 100 g seed and solution of Actellic 25 .E.C®  (Pirimiphosmethyl) which were applied at 0.00, 0.20, 0.30 and 0.40 ml/ 100 g seed. Jatropha curcas seed oil and Actellic caused mortality of adult C. maculatus, suppressed oviposition and inhibited adult emergence. Actellic at the lowest concentration (0.20 ml/ 100 g seed) caused 66.67 % mortality of adult C. maculatus in the first 48 h of exposure and reduced ovipostion by 70.00 %. Jatropha curcas seed oil at the highest concentration (3.00 ml/ 100 g seed) caused 60.00 % mortality of the bruchid in 48 h of exposure period, reduced oviposition by 56.67 % and decreased seed damage by 76.67 %, when compared with the untreated control which recorded 96.67 %  oviposition and seed damage by the bruchid, respectively. Actellic treated seeds had the best protection with weevil protection index (WPI) of between 0.00 – 6.67 %, followed by the seed oil, (16.67 to 33.33 %). These results differed significantly (P<0.05) from the root extract which gave the lowest (46.67 – 53.33 %) protection index. The root extract performed poorly and could not compare effectively with either the seed extract or synthetic chemical. The residual test results were not statistically different from the first trial (P=0.05). J. curcas at high concentration (2.00 and 3.00 ml/ 100 g seed) compared most favourably with the lowest concentration of Actellic 25 .E.C®. The treatment materials had no significant effect on the germination of stored cowpea seeds. J. curcas seed extract gave significant protection to stored cowpea seeds against C. maculatus and could serve as alternative to synthetics in the management of cowpea bruchids.  
 Keywords: Mortality, Oviposition, Emergence, Weevil Perforation Index, Germination