Globally, leopards are the most widespread large felid. However, mounting anthropogenic threats are rapidly reducing viable leopard populations and their range. Despite the clear pressures facing this species, there is a dearth of reliable population estimates for leopards across their range, which is particularly important in landscapes consisting of protected and non-protected areas. We used leopard data obtained from camera trap surveys in 2013, 2018 and 2022 to estimate population abundance and density using robust spatial capture-recapture models in a major carnivore site in Nepal. Leopard population in Chitwan National Park, its buffer zone and adjoining forests was estimated 107 (95 % CI: 81–144) with density 3.95 (95 % CI: 2.76–5.2) leopards per 100 km² in 2022. We documented stable leopard population with a slight decline from 58 (37–77) in 2013 to 48 (34–66) in 2022 in the park. Competition with increasing tiger numbers is a likely consequence for leopards and other carnivores in the protected area. Lower prey density, human-carnivore conflict through livestock depredation, and canine distemper virus with a large domestic dog population are major threats to leopards outside the park. To reduce these threats, we suggest that conflict mitigation measures be intensified, and the impact of disease on large carnivores quantified in this important carnivore landscape.