Skin cancer is epidemic. Sun safety behaviours of skiers and snowboarders have not been investigated despite prolonged exposure at high altitudes. A sample of 156 adult alpine skiers and snowboarders at 14 high-altitude ski resorts in the western United States were interviewed during 1996-97 to ascertain their sun protective actions and exposure. Few of the adults said they received any messages over their entire lifespan regarding sun safety while skiing or snowboarding. Sun protective behaviour was variable: it was negatively associated with being male, younger, a snowboarder, exposed to prevention messages, and being in cold, windy and cloudy weather, and positively related to chair-lift elevation, skin sun sensitivity and prior sunburning while skiing or snowboarding. Prevention programs should target the young, males, novices and snowboarders, and advocate protection throughout the season and during inclement weather.