A noninvasive method of assessing the degree of sun-induced skin damage was used to estimate the prevalence of skin damage in teenagers in four cities in Australia and one in Scotland. Information about age, sex and complexion characteristics was obtained from 1307 students aged 13 to 15 years. Silicone rubber casts were taken of the skin of the students' hands and classified as showing either no or mild skin damage. Between 40 and 70 per cent of the Australian students had detectable skin damage, compared with about a third of Scottish students of the same age. In a multivariate analysis, the risk of having sun-damaged skin in the teenage years was up to seven times higher for Australian residents than for Scottish residents. Other risk factors were male sex (odds ratio (OR) 4.3), blistering on exposure to sun (OR 2.6), and having blond hair (OR 2.0), red hair (OR 5.3) or freckles (OR 2.7). The high prevalence of sun-induced skin damage at such a young age reinforces the need to encourage sun-protection behaviour in Australian children and teenagers.