This study investigates the contemporary urbanization process of sub-Saharan Africa. The region is predicted to experience a surge in urban population growth the forthcoming decades, yet why and how this is happening is not very clear. Theory often considers urbanization to be a part of a modernization process where people migrate from rural areas to urban. But depictions of reality suggest that rural-to-urban migration might be less significant than previously thought, and neither is it given that urbanization causes prosperity in sub-Saharan Africa. This thesis tries to complement the gap of knowledge regarding the mechanisms of urbanization in sub-Saharan Africa. Statistical data is organized and assembled by using the structured, focused comparison method and then analyzed in order to create an understanding of urbanization and urban population growth in this particular region. The result of this study suggests that the mechanisms for urban population growth change over time. Urban population growth is often thought to be driven by rural-to-urban migration. However, nowadays there is a correlation between urban population growth and population increase, which did not exist a couple of decades ago. It is clear that urbanized countries are, typically, more advanced regarding economic growth, but it is unsure whether this factor affects socio-economic development. The findings underscore the vast complexity of urbanization and urban population growth, as well as the heterogeneity of sub-Saharan Africa. Yet there is potential for a new theoretical framework that can provide explanations to the processes sub-Saharan Africa is expected to undergo.