Mothers in contemporary western societies are expected to adhere to the principles of intensive parenting, spending a great deal of time and effort caring for their children, protecting them from risks and promoting their health, development and wellbeing. This paper draws upon research involving indepth interviews with 60 mothers of infants and young children living in Sydney. The discussion focuses in detail on three major topics discussed in the interviews: how the interviewees conceptualised good health and illness in their children; the role of diet and physical exercise in promoting children’s good health; and space, physical safety and bad influences. The study found that the interviewees reported that they ‘read the signs’ of their children’s bodies and had to ‘know’ their bodies intimately in order to do so. They also interpreted the signals of their own bodies – their ‘gut instincts’ – as part of the process of maintaining careful surveillance of their children’s health state. They represented diet and physical exercise as the most important dimensions of promoting their children’s health, and were very concerned about the risk of obesity in their children. Notions of space and judgements about the bodies within these spaces were also important to some of the women’s concepts of protecting their children’s health and wellbeing.