Island biodiversity has a notorious record of decline and extinction which continues due to habitat loss and degradation, invasive species, overexploitation, pollution, disease and human-forced climate change. In terrestrial systems, these global and local pressures are more acute because of relatively small land to sea area, high endemism and poor adaptations to resist predation. Regional policy and learning frameworks exist to combat biodiversity loss and environmental degradation, but implementation remains patchy across the 22 Pacific Island countries and territories (PICTs) within Oceania. PICTs are challenged by small, under-resourced government departments, limited data, and strong political will for rapid economic development at the cost of ecological sustainability. In this synthesis of the special issue, we identify the challenges and opportunities for biodiversity conservation on Pacific islands.