Using qualitative data collected from a sample of rural-urban migrants over the age of 15 in two Nairobi slums interviewed in 2008, this paper discusses the migrants' extent of satisfaction with their residential location and decision to migrate. The study sheds light on why people continue to migrate to, and stay in, the rapidly growing slum settlements despite the high levels of poverty and poor health conditions in these areas. Tenure status is related to satisfaction for all ages. Environmental factors were frequently mentioned as a source of dissatisfaction. Life cycle and 'age-cohort effects' may also affect satisfaction for different age groups in terms of who is satisfied as well as the issues that are considered for satisfaction. High levels of dissatisfaction with slum life may be responsible for high out-migration in slum areas, although it does not mean that those who remain do so because they are satisfied. At the same time, challenges associated with slum life do not automatically signify dissatisfaction. Perceived success, as well as conditions in the area of origin can be used to explain and understand satisfaction/dissatisfaction with slum life. Satisfaction with migration and residential location may be related not only to the destination place, but also to events in the area of origin.