We characterized the dietary pattern of Malayan sun bear Helarctos malayanus from three seasons in Namdapha tiger reserve, Arunachal Pradesh, India. Eighty five scat samples were collected between August 2008 and November 2010. Scats were analysed both qualitatively and quantitatively to determine the food composition of sun bear in the region. The contents were manually separated and examined. Cumulative frequency was used to determine the contribution of food items in the diet of sun bear. Malayan sun bear was observed to feed on a wide variety of food items. Coleoptera were the most frequently occurring food item in their diet. Sun bear consumed 10 plant species. The items/species area curve was developed to find the minimum number of scats required to study the dietary composition. Food of animal origin comprised of the class Arachnida, Insecta, Mammalia and Osteichtyes. Sun bear were also found to feed on 15 families of insects that were mainly from the order Coleoptera, Hymenoptera and Isoptera. Among 15 families, 14 insects were identified as regular food items of sun bear in the study area. Presence of rodents and scorpions in food of sun bear was also recorded. Among these, 8 families of beetles (Coleoptera), one family of stingless bee (Apidae), one family of ants (Formicidae) and one wasp (Vespidae) could be identified.