This dissertation presents the transit experiences of migrants from Sub-Saharan African countries in the Turkish metropolis of Istanbul. Although the narratives of the individuals met in the course of fieldwork in Istanbul are the primary focus, the thesis also outlines the larger macro-structural conditions faced. The overarching goal of this thesis is thus, through the experiences of the migrants themselves, to critically approach and discuss the concept of transit with the aid of the theoretical perspectives of social networks analysis and mobility. Based on ethnographic fieldwork and an explorative design, this thesis investigates the ‘black-box’ that the state of transit has hitherto often represented in the literature by focusing on migrants’ experiences of mobility, immobility and social networks. Insecurity, uncertainty, and an overall precariousness constitute the state of transit. Light is shed on questions relating to the peculiarities of a state of transit and its impact on everyday life. The thesis highlights the processual nature of mobility and immobility strategies. The issue of migrant capital (conceptualised as local knowledge, with a particular focus on the migrant experience) is found to be a crucial aspect of immobility in transit. The thesis further identifies a pattern of social stratification based on immobility intersected with legal status and migrant capital, and argues that this stratification is produced by transit movements and, in turn, reproduces transit movements. Related to social stratification is the presentation of Istanbul as the socio-economic context that offers prerequisites for establishment in situ and establishment in mobility.