The aim of this study was to evaluate the caries prevalence in 8-, 12- and 15-year-old Westphalian children from 1990 to 2001 and to analyse caries experience in children attending schools with different educational level. Caries was diagnosed according to WHO criteria (1987), the DMFT was calculated (SAS database) and comparisons were made (Tukeys student range test; á = 0,05). In 8-year-olds the mean DMFT remained unchanged over the ten-year period with 0.3 DMFT. The proportion of caries free children increased from 80.7% in 1990 to 86% in 2001. In 12-year-olds caries declined from 2.1 DMFT in 1990 to 0.9 DMFT in 2001. The proportion of caries free children increased from 35% in 1990 to 86.6% in 2001. A DMFT of 4.3 was revealed in 15-year-olds in 1990, and 1.6 DMFT in 2001. The proportion of caries free children in 1990 and 2001 increased from 19.8% to 48%. Comparing different educational levels, the caries prevalence of 12-year-olds visiting grammar schools declined from 1.8 to 0.3 DMFT, and from 3.2 to 1.0 in 15-year-olds within ten years. Children visiting secondary modern schools showed a declining prevalence from 2.5 to 1.8 DMFT in 12-year-olds, and from 5.2 to 2.7 DMFT in 15-year-olds. In students of junior high-schools the DMFT decreased from 2.2 to 0.8 in 12-year-olds and from 4.3 to 1.3 DMFT in 15-year-olds.In summary, during the last ten years a substantial caries decline was observed in Westphalian schoolchildren, but this improvement in oral health differed significantly in dependence of the educational level. Schlagwörter: caries, epidemiology