This paper reports data on the first national survey of sun-protection measures of Australian secondary school students. A cross-sectional survey of a representative sample of 23,915 Australian school children in Years 7-12 was conducted in 1993. Students were questioned about usual sun-protection practices, beliefs about skin cancer and suntans, and sunburn history. The results showed differences in sun-protection behaviours as a function of 'year level', 'gender', 'skin type' and 'concern about getting cancer' among others. Adolescents who believe there is a lot they can do to avoid skin cancer are more likely to engage in sun-protective behaviours. Males were more likely to wear a cap, yet females tended to use sunscreen. The use of clothing to protect themselves from the sun was higher in males, yet females were more likely to stay mainly in the shade. All behaviours decreased with age. Poorer protective practices were also associated with increased sunburn, except for sunscreen use where the converse was the case. Suntan was still a desire for adolescents. While there is considerable room for improvement in the sun-protection behaviour of adolescents (particularly those in higher grades), most students usually take some precautions. However, by Year 12 (17 and 18 year olds) less than half report usually wearing a hat and just two-thirds reported usual sunscreen usage.