Background In recent years, healthy eating messages have sought to highlight the advantages of a healthy balanced diet, but there is little evidence that the recommendations have been translated into sustained behavioural change. In Scotland, the national diet has become a major focus in key policy documents, and the diet of children and young people has been consistently highlighted as an area of particular concern. This paper reports on dietary trends among Scottish schoolchildren during the 1990s.Methods Data were collected from a representative sample of Scottish schoolchildren as part of the WHO Cross-national Health Behaviour of School-aged Children (HBSC) study. Three consecutive national surveys were undertaken in Scotland, in 1990, 1994 and 1998, using self-completion food frequency questionnaires with 11-, 13-and 15-year-old school pupils.Results Between 1990 and 1998, fruit and vegetable consumption increased among Scottish schoolchildren, especially among girls, but levels of consumption fell below current dietary recommendations. There has been a concomitant increase in consumption of high-fat and high-sugar foods, and consumption of these foods is higher among boys and children from lower socio-economic groups.Conclusion The findings emphasize the need for continued health promotion efforts to improve the diet of schoolchildren in Scotland especially among lower socio-economic groups.