Tropical forests are threatened due to forest clearing and fragmentation which lead to a decrease in forest cover area and landscape connectivity, while also increasing edge effects. These impacts affect biodiversity and ecosystem service provision which are essential for humanity’s well-being. Protected areas are created to minimize these effects on biodiversity, but many of them are threatened due to forest fragmentation in the surrounding areas. Thus, forest restoration is needed to ensure the suitability of protected areas in the landscape. However, restoration planning needs to adopt an ecological landscape approach to ensure the recovery of the biodiversity and the ecological processes. This study developed a forest sustainability index (FSI) which represents the forest patch potential in facilitating landscape restoration in a protected area and its surroundings. A land-use/land-cover map was used to calculate landscape metrics at two levels: landscape and patch. Landscape metrics were subsequently selected to create the index. The tested landscape presents a great number of fragments with most of them being small in size and having irregular shapes. The focus areas for forest restoration are located close to forest fragments with higher FSI values, as these can facilitate natural restoration and guarantee the maintenance of the ecosystem processes.