This contribution critically explores changing relationships between diamond mining and patterns of urbanisation in Sierra Leone. In providing an historical overview of mining expansion and contraction, the paper highlights the significant impacts that mining has had on the rural–urban continuum, and how this has shaped political, economic and social change in diamondiferous regions. Focusing on Kono District, the effects of diamond mining on populations are evaluated before, during and after the civil war, demonstrating how diamonds have had diverse and varying impacts on both population mobility and urban agglomeration at different points in time. While much attention has focused on the social consequences of wartime displacement from diamondiferous areas to the capital city, Freetown, recent research suggests that the post-war return of young people to diamond mining regions has had unexpected consequences. Most significantly, a decline in artisanal mining activities and the rise of large-scale industrial mining has reawakened the interest of young ex-miners in farming, especially those who enjoy hereditary land rights. While one consequence of the war may be that the population is now more urban and more mobile, the paper concludes that the return of young people to their villages of origin, and rapprochement with local chiefs, may be helping to drive a resurgence of community-based cooperation in Kono District, a development which could provide a more durable basis for sustainable and democratic development in the years to come.