In June 2006, there were 4 million children aged under 15 years in Australia, representing one-fifth (19%) of the total population (ABS 2006a). Health gains brought about by better living conditions, education, medical care and vaccination would suggest that this generation of children should be the healthiest ever (Patton et al. 2005). However, there are emerging concerns related to rapid social change and the associated new morbidities such as increasing levels of behavioural, developmental, mental health and social problems (AIHW 2006). Early childhood in particular has become a key priority for Australian government and non-government organisations (AIHW 2006).