The aim of present study was to optimize the radiation dose for maximum reduction of aflatoxin content by varying the distance between the contaminated peanut samples and the UV-C light source and duration of exposure to UV-C light. Studies were also undertaken to evaluate the effect of UV-C exposure on the various quality parameters of peanuts. Two different studies were conducted in a sterilized wooden box fitted with a 15 W UV-C tube in the centre at the top of the box, where the contaminated samples were placed at a distance of 15 cm and 30 cm respectively from the UV-C light source. The duration of the exposure was varied from 2 h to 12 h. The fungicidal activity of UV-C radiation was found to be more pronounced in peanuts exposed at a distance of 15 cm. Maximum reduction of aflatoxin concentration in both the studies was found after 10 h of exposure. In the studies, conducted at a distance of 15 cm, aflatoxin concentration reduced to 99.1 % (350 ppb to 3 ppb) with decrease in fungal count to < 10 cfug-1and at a distance of 30 cm, reduction of 97.4% (350 ppb to 9 ppb) of the aflatoxin content with< 10 cfug-1 of fungal count was observed. However, the quality parameters including nutritional values and physico-chemical parameters of peanuts remained relatively unaffected (within the national and international regulatory limits). The present study thus provides a validated practical method of using UV-C irradiation to reduce aflatoxin contamination in peanuts, intended to be used for the purpose of food and feed.