The low-lying atoll states of Tuvalu and Kiribati have gained international attention due to their vulnerability to climate change and associated sea-level rise. They have been referred to as 'sinking islands', with some commentators predicting they could become completely uninhabitable within a generation. This work acknowledges that climate change is having a negative impact on these island communities. However, it would be too simplistic to only focus on this as the key factor in patterns of migration from the outer islands to the urban centres of each state. There are multiple drivers for both internal and international migration, and also for the desire to reside in these communities for as long as they remain habitable. Through fieldwork interviews with residents of Vaitupu, an outer island of Tuvalu and Abaiang, an outer island of Kiribati, this work seeks to understand the key determinants in residents deciding whether or not to relocate. Interviews were also conducted with former members of these communities that are now resident in the respective urban centres of Funafuti and Tarawa. Further context was supplied via interviews with government officials, donor agencies and civil society groups.