Research shows that lack of car ownership is associated with poorer health. It is often assumed that the reason for this observed relationship is that access to a car--or not--reflects access to household assets. Consequently, lack of car ownership is used as a standard marker of low socio-economic status. However, little attention has been paid to the experience of carlessness in the context of disadvantaged lives. This paper argues that "no access to a car" is not only an indicator of low socio-economic status but of walking as a mode of transport. These arguments are illustrated by data from a study of 30 low-income mothers with young children. Although walking is promoted as both an excellent and inexpensive form of exercise, these data suggest that reliance on walking can have negative effects on the welfare of families. The paper draws on qualitative data to describe the ways in which carlessness restricts access to health and social care resources such as food shops, health-care services and social networks. It also explores the impact of walking on the well being of mothers and their day-to-day relationships with children. This is compounded by walking through areas that are neglected and depressed. The paper concludes that strategies to reduce social exclusion must recognise the contradictory health effects of walking and aim to regenerate the physical fabric of social housing estates as well as improve public transport options.