This study compared the prevalence of emotional and behavioural problems experienced by 10-11 year old and 14-15 year old children living in single-parent and two-parent families in South Australia. The 10-11 year old male children living in single-parent families were found to have significantly more emotional and behavioural problems than 10-11 year old male children living in two-parent families. In particular, the younger male children living in single-parent families experienced more externalizing behaviour problems than younger male children living in two-parent families. It is suggested that paediatricians and general practitioners need to be aware of children who are at particular risk for developing emotional and behavioural problems, and the approaches which may be employed to provide help.