Protected areas (PAs) are extensively used as one of the most important strategies for biodiversity conservation. They can contribute to maintaining or recovering biophysical structures, processes and functions of the ecosystems within the PA and even around it. However, the management of most PAs is facing a growing set of challenges due to climate change, unsustainable use of resources, and other socio-economic perturbations, especially in the surrounding landscape of the PAs. Therefore, it is crucial that the PA´s management know and understand the nonlinear relationships and feedback loops affecting the socioecological system (SES) in which the PA is embedded. This research selected Parsa National Park (PNP) in Nepal as a case study to analyse its SES, using the ecosystem approach. PNP, whose status has recently been changed from a wildlife reserve to a national park, is one of the 20 protected areas in Nepal and is located in the intersection of the Tarai and Siwalik physiographic zones. It has a very important socioecological role in facilitating the connectedness of different ecosystems – it enables the mobility of wild animals across these two zones – as well as in providing many ecosystem services such as the provision of nontimber products, carbon sequestration, control of erosion rates, buffering and attenuation of mass flows, micro and regional climate regulation, and water flow maintenance, among others. The purpose of the study was to develop a systemic analysis which includes visualizing and describing the SES in order to identify the key elements, patterns, trends and complex relationships in the system and, based on that, to understand how the emergent properties of the system can arise and influence its sustainability. The method “adaptive MAnagement of vulnerability and RISk at COnservation sites” (MARISCO) framed the methodology that was applied. It included a systematic literature review of secondary sources, semi-structured interviews, and a validation workshop with the stakeholders. This study confirms that PNP is clearly embedded in an SES which goes beyond the administrative boundaries of the PA. The interdependence and complexity of the relationships identified within the SES and with the surroundings suggest that cross-scale and multilevel perspectives need to be included in the PA´s management paradigm. The study has also identified that the main ecological dynamics that have been affected are those related to the hydrological system and the connectedness of the landscape. Even though climate change is altering precipitation and temperature patterns, the main drivers affecting the system dynamics are mainly attributable to human activities. This creates a set of challenges for transforming the development pathways in Nepal towards a more sustainable model. The results show the need to promote adaptive governance in order to frame the implementation of an adaptive management programme in PNP; this includes adopting a participatory approach whereby the ecological knowledge of the local population is taken into account, and also by promoting a culture of shared learning. The present study lays the groundwork for future research to improve the understanding of the dynamics of the SES of PNP, to incorporate the ecosystem approach into PNP´s management, and even to scale it up to the entire landscape. Taken together, these findings have significant implications for the understanding of how the SES of a PA influences its sustainability in the short, medium and long terms.