We investigated the occurrence and diet of two sympatric mongoose species; the small Indian mongoose Urva auropunctatus and the grey mongoose Herpestes edwardsii inhabiting Margalla Hills National Park, Islamabad, Pakistan. The two species occurred in the park at elevations between 537 m and 1363 m a.s.l., with the grey mongoose occurring at higher elevations than the small Indian mongoose. Out of 23 sites sampled, only three were common to both mongoose species. The diet of mongooses, determined through food remains in scats, comprised of small mammals (rodents, shrews), insects, birds, reptiles and seeds and fruits. Rodents were the most frequently-consumed prey species of both mongooses during summer and winter, whereas insects were consumed more frequently during the summer. The small Indian mongoose showed a wider niche breadth than the grey mongoose, but the overall dietary overlap between the two mongoose species was high with a value of 0.93. Our results support the idea that these sympatric mongoose species may reduce interspecific competition for food with each other through spatial adjustments in their habitat use.