The natural defense against peroxidative damages inflicted by oxygen derived free radicals is provided by antioxygenic enzymes. Feeding of exogenous antioxidants increases the life span of insects by decreasing age-independent susceptibility to death. The present study describes the effect of L-ascorbic acid on the life span, catalase activity, and lipid peroxidation in Callosobruchus maculatus, a non-feeding insect. Life span studies were carried out on insects emerging from unsoaked, water soaked and ascorbic acid (0.1, 0.5, 1.0, 50, 100 and 250 mM) soaked seeds. The increased life span at 1 mM ascorbic acid concentration was accompanied by declined mortality rate, age-independent susceptibility to death, lipid peroxidation and increased catalase activity in both sexes of the insect. The differential distribution of catalase activity with respect to age and sex in whole body homogenates was observed in the insects. The increased longevity of C. maculatus on ascorbic acid treatment could be attributed to a decline in lipid peroxidation and increase in catalase activity of the insects.