Evaluation of efficacy of black pepper (Piper nigrum L.) and cumin (Cuminum cyminum L.) seed powder against Callosobruchus chinensis L. infesting green gram revealed a dose-dependent adult mortality and a positive correlation with period of exposure. A complete adult mortality was observed with P. nigrum seed powder @ 1 g/ 100 g seed as against 60% adult mortality with C. cyminum at 72 hr after treatment (HAT). The LC₅₀ values of P. nigrum and C. cyminum seed powders were observed as 0.16 and 1.47 g/ 100 g of seed at 48 HAT. Both P. nigrum and C. cyminum seed powders showed strong ovicidal properties, and affecting the adult emergence to an extent of 0 and 6% when used @ 10 g/ 100 g seed as against 90-91% in untreated control.