Effect of three doses of nuclear polyhedrosis virus viz., 5.40 í— 108, 5.40 í— 105 and 5.40 í— 103 polyhedral occlusion bodies (POBs/ml) on consumption, digestion and utilisation of sunflower leaves by 8 days old larvae of Helicoverpa armigera (Hiibner) was studied for a period of 5 days, The food intake, faecal matter production and weight gain of virusfed larvae were significantly lower than those of healthy ones on the fourth and fifth day of inoculation and showed dose-dependent tendency, There was weight gain by both control and virus-fed larvae up to third day, after which the virus-fed larvae lost weight in contrast to gain in weight by control larvae. The approximate digestibility did not show effect due to virus infection. The growth rate, gross and net efficiency of food utilisation were altered during the virus infection.