An experiment was conducted to obtain information on the estimation of the reduction of yield of bidi tobacco due to different degrees of infestation by leaf eating caterpillar,Prodenia lituraF. It was found that the reduction in yield was to an extent of 23.4, 44.2 and 50.4 per cent when the plants were infested with 2, 4 and 8 larvae per plant respectively, which gave a financial loss of Rs. 489.60 to Rs. 1,053.45 per hectare at Rs. 1.50 per kg., the average price of tobacco during the years under experiment.