A laboratory experiment was conducted to study the effect of different levels (0 beetle, 1 pair, 2 pairs, 4 pairs and 8 pairs) of Callosobruchus chinensis infestation on seed deterioration of pigeonpea (var. UPAS 120) and greengram (var. K. 851) under ambient conditions (27 ± 4°C temperature and 84 ± 10% relative humidity). The results indicated that in both pigeonpea and greengram the level of bruchid infestation was directly proportional to the population count and per cent seed infestation but inversely proportional to the germination per cent. Mycoflora infection was noted in all the treatments but at higher level of infestation high bracterial infection suppressed the fungal invasion