Most European children experience exposure to the sun during the summer holidays. The aim of this study was to examine the behaviour of European children when in the sun during their holidays. In 1995-1997, a total of 631 young children were recruited during a multicentric study in Belgium, Germany, France and Italy. For each holiday period from birth, parents gave detailed information on sun exposure and child behaviour. Predictors and trends over time of sun protection were investigated. Forty percent of children were exposed to sunlight in the first and 86% in the sixth year of life. At the same time, the number of children who experienced sunburns rose from 1 to 23%. In the whole period of 6 years, only 8% of children always wore trousers and shirt when in the sun, while 25% children always used a sunscreen. The proportion of sun-exposed children who used sunscreen was stable with age (approximately 50%), while those who always wore trousers and shirts dropped from 46% (1st year) to 19% (6th year). Multinomial logistic regression showed that sunscreen use, but not the wearing of clothes was associated with sun-sensitivity. In summary, sun exposure increases steadily, while sun protection decreases in the first 6 years of life in our cohort of children. In this cohort, use of a sunscreen was much more frequent than the wearing of clothes and a reduction in sun exposure.