The biodiversity of the oceanic islands of the Gulf of Guinea is valued internationally for its uniqueness and locally for its contribution to human welfare, but it is under growing anthropogenic pressure. We provide an overview of recent progress, ongoing challenges, and future directions for terrestrial and marine conservation. The islands were colonized in the late fifteenth century and have since relied heavily on international markets. Nevertheless, the livelihoods of many islanders depend directly on local natural resources, and growing human populations and economies are intensifying the use of these resources, including timber, land, and fisheries. Here we summarize conservation initiatives on the islands, including pivotal projects and achievements, as well as the rise of civil society and governmental engagement. We also review species and site-based conservation priorities and highlight the need for continuous updating based on ongoing research. Engagement in conservation has increased steadily in recent decades but not fast enough to counteract the growth of anthropogenic pressure on biodiversity. Fostering capacity building, environmental awareness, and research is thus urgent to ensure a thriving future for the islands, able to reconcile economic development and biodiversity conservation.