Brown Mongoose Herpestes fuscus is crepuscular in habit and rarely encountered. Information on its natural history and ecology is limited and consequently its conservation requirements are not well understood. We report observations of a Brown Mongoose feeding on a Nilgiri Langur Semnopithecus johnii carcass in the Kalakad Mundanthurai Tiger Reserve, southern India. A camera trap was deployed over the Nilgiri Langur carcass over 10 nights during which, the mongoose visited the carcass on eight nights. Based on the images captured, the mongoose behaviour was broadly categorized as vigilance, feeding, walking and grooming. The mongoose was most active between 03.30–06.00 h and 19.00–00.00 h. Additionally, we report observations of a pair of Brown Mongoose foraging, and an incident of road mortality. These observations will add to the limited current understanding of the species, necessary for assessing its conservation status and identifying interventions.