A health survey of 551 high school students in the coastal town of Busselton, Western Australia, was undertaken in November, 1977. Physical measurements showed that approximately 17% of the boys and 24% of the girls were overweight (115% or more of their standard weight for height and age). Blood pressures ranged from 108/64 mmHg at 13 years to 129/70 mmHg at 17 years for boys, and 109/63 mmHg to 116/66 mmHg for girls of the same age group. Fasting plasma glucose, cholesterol and triglyceride values were also obtained. Twenty-seven per cent of the girls and 17% of the boys were regular smokers, a habit often acquired by the age of 12 years. Most of the children watched television from two to four hours daily during the week, and for longer periods at weekends. Although most had satisfactory levels of physical fitness, there was a trend towards poor performance in overweight children, and there was a significant decrease in participation in regular sports by the older teenagers.