Forest fragmentation is overwhelmingly the result of changes in land use and the development of infrastructures. It can be considered as the spatial manifestation of deforestation and degradation in a landscape. Forest fragmentation thus results in the same loss of ecosystem services as these other forms of land-cover change, but how does it affect livelihoods? We propose here an analysis of the livelihood impacts of tropical forest fragmentation, which will begin with a better definition of the spatial processes involved in fragmentation. As it is difficult to analyse the impacts of fragmentation without consideration of the associated impacts of the causes - or drivers - of forest fragmentation, we will analyse them in detail. Fragmentation results from a range of drivers that are categorized into five groups: (i) economic factors; (ii) governance factors; (iii) demographic factors; (iv) technological factors; and (v) cultural factors. Economic factors are prevalent in decisions, with forest conservation often being a luxury for wealthy people. Stakeholders who gain direct economic returns from deforestation - from logging, farming and facilitated access to markets - will also benefit globally from forest fragmentation, the benefits from these drivers by far outweighing the loss of ecosystem services. However, forest dwellers and isolated forest communities will often have to choose between 'modern' life or the cultural specificities that shaped their identity. Throughout the chapter, the forest-transition curve is used as a heuristic framework to understand the relationships between human development and the loss and fragmentation of forest cover.