Containing 1,804 km2 of lowland tropical rainforest, Sapo National Park (SNP) is Liberia’s largest and oldest protected area (PA). It holds many threatened and endemic species including some of the largest populations in Liberia of the western chimpanzee Pan troglodytes verus (CR), the Pygmy Hippopotamus Choeropsis liberiensis (EN), the Jentink's Duiker Cephalophus jentinki (EN), and the Forest Elephant Loxodonta cyclotis (VU). Established in 1983 by an executive order during a military regime, with its boundaries extended in 2003, Sapo has been managed with limited consultation of and engagement with communities surrounding the park. However, in recent years, Liberia has adopted more community friendly management approaches to protected area management, with two landscapes currently co-managed with communities. Despite this trend, the management approach at Sapo National Park has remained relatively militarized. Over the last few years, relationship with local communities has further deteriorated as complaints about the nature of the 2003 extension of the Park, coupled with complaints of crop raiding and the FDA’s approach to park management, have further alienated communities. To complicate the situation even further, the Forestry Development Authority, the government agency responsible for the park, has been unable to provide all of the resources needed to effectively manage the park. This led to a surge of illegal activities, particularly mining and hunting, that now threaten the ability of Sapo to protect biodiversity. We present the outcomes of a social assessment aimed at improving understanding of communities’ perception of park-related impacts on their livelihood and well-being, to inform the process of enhancing the effectiveness of park management, by providing a platform through which communities can be more involved in the park management. Using the Social Assessment of Protected Areas (SAPA) methodology, we assessed the impact of Sapo National Park in 50 communities surrounding the landscape. We show results of this process to demonstrate its effectiveness in collecting information aimed at integrating communities’ and management’s interests and concerns, for effective PA management. The result of the assessment has informed the revision of the Park’s management plan, which provides a role for communities to support the management of the park. Additionally, we demonstrate real-world value of using the information from the social assessment to peacefully resolve a volatile situation between the national park authorities and communities. Finally, we present the challenges and lessons learned in introducing community-friendly management approaches in a slow progressing but traditional protectionist setting.