The demise of vital ecosystems has necessitated the designation of protected areas and formulation of policies for their sustainable management. This study which evaluates policy implementation in Digya National Park in the Volta Basin of Ghana, was prompted by lack of information on how Ghana Forest and Wildlife policy, 1994, which regulates DNP, is being implemented amidst continues degradation of the Park. The methodology adopted involved interviews with government officials and analysis of institutional documents. The results revealed that financial constraints and encroachment are the main problems inhibiting the realization of the policy goals, resulting in a steady decrease in forest cover within the Park. The study recommends intervention measures including proactive government role in capacitating implementing agencies to function more effectively, more community participation and private sector partnership in the implementation process. The study concluded that successful policy implementation at DNP would above everything help ensure the sustainability of Volta Lake and its hydro-electric power plant.