For cultural and economic reasons, Botswana has one of the most mobile populations in the world. People move around the country frequently for employment opportunities and because of the nature of the settlement patterns. Also, there is extensive multi-partner sexual activity in the country. This study analyses the relationship between population mobility and multi-partner sex and their implications for the spread of HIV and AIDS in Botswana. The unit of analysis is a sample of 292 mobile working in rural and urban settings in four selected districts of the country.