The effect of methionine on longevity, antioxygenic enzymes and lipid peroxides in Callosobruchus maculatus was investigated using C. maculatus maintained on Vigna radiata seeds soaked in seven levels of methionine, 0, 1, 3, 5, 7, 9 and 12 mg/ml water. The life span and activities of catalase and peroxidase were higher in Callosobruchus maculatus infesting Vigna radiata seeds soaked in methionine as compared to their control cohorts. However, the lipid peroxide (malondialdehyde; MDA) levels generally remained unaltered. The present observation on the increased longevity in C. maculatus with methionine level is an extension of earlier findings on its anti-ageing effect in higher animals.