Animal populations monitoring within and outside the park is important for identifying mammal communities but also for designing conservation plans. We assessed the diversity and the relative of medium and large mammals in and outside of Moukalaba-Doudou National Park, Gabon, using camera traps. The cumulative time for all functional camera traps was 3060.42 camera-days in the park and 2880.68 in the buffer area. Overall, of 30 medium and large mammal species and 3 rodent species were detected in the park, whereas 25 species and 3 rodent species were detected in the buffer area. Moreover, the forest dwelling species were more abundant in the park than in the buffer area (p = 0.018) and most of savanna dwelling species were more abundant in the buffer area (p < 0.001). In both areas, duiker species were more abundant than other detected species. However, the ratio red/blue duikers revealed a high hunting pressure in the buffer area. We succeed to identify at least 5 groups with more than 7 individuals within the park and 3 in the buffer area. Implementing a habituation process in the buffer area will require prior consultation with the local populations to ensure they refrain from hunting. Gorilla habituation could be used as a stool of protecting biodiversity but also of enhancing the benefits to the communities through community-based ecotourism.