Within the first 3 years of life, 16.9% of infants experience asthma or wheeze. Among non-asthmatic children aged 4 to 5 years, 4.1% will develop asthma by the seventh year of life. These and other new insights into the incidence, natural progression and outcomes associated with childhood asthma are presented in this report, based on analysis of Growing up in Australia: the Longitudinal Study of Australian Children.