In sub-Saharan Africa (SSA), motorcycles are playing a major role in daily mobility and access to the city, as well as in the local economy. Walking remains the most common mode of daily travel but it does not provide city-wide mobility. Given the cost of the car and the marginal role of the bicycle, the motorcycle is the main alternative to conventional public transport. It weaves its way through congested roads and provides access to remote suburbs. In that context, the number of households owning a personal motorcycle is increasing, whereas motorcycle taxi services are developing fast. The aim of this paper is twofold. First, it presents an overview of the spread of motorbikes in SSA and their use. Second, it discusses two major public health issues linked to this boom: the increase in road accidents and the contribution to growing air pollution. Data remain scarce on motorcycle equipment and use in SSA. In order to address this lack of statistical data, we used two datasets. We gathered Development and Health Survey results to provide information on the evolution of household motorcycle ownership rates across SSA. Then we analyzed microdata from a household mobility survey (Dakar, Senegal) and from a survey of transport users (Lomé, Togo) to characterize the uses of motorcycles and the daily mobility they allow. In Lomé, motorcycles are very common, whereas in Dakar, they are more marginal. The results highlight a strong variation in motorcycle ownership rates between regions in SSA and between urban and rural areas. Personal use of motorcycles is often long-standing and may be combined with commercial use. Analyses of surveys in Dakar and Lomé show that personal motorcycle users are more male, younger and wealthier than public transport users, and more male and younger but less wealthy than car users. Motorcycle taxi users are more female and less wealthy than personal motorcycle users. The environmental and public health issues raised by the rapid growth in the personal and commercial uses of motorcycles call for real improvements in the public regulation. From this perspective, the lack of data on urban mobility and its impacts limits decision-making and the implementation of appropriate policies. A major challenge is to improve administrative and survey data in SSA cities.