The pattern of sugar consumption in a sample of 350 11-12-year-old adolescents was examined. Their knowledge of the sugar content of a range of common foodstuffs was also investigated. There were only small differences between the social class groups in mealtime sugar consumption. The frequency of total food and drink was significantly higher in the low social class groups and this was mainly explained by significantly higher between meal consumption of solid food which contained sugar. The level of knowledge of the sugar content of foods was significantly higher in the higher social class groups. Fifty-two per cent of the questions were answered correctly, with a range of 9-91 per cent for individual foodstuffs.