Aim of this 2-year follow-up study was to assess the dental health status and the caries pattern of first permanent molars in German and immigrant children. 300 German and 69 immigrant children living in the Westphalian Ennepe-Ruhr district were involved in this study. The mean age of the population was 8.0 years at the baseline (1997) and 9.8 years at the second examination. The surface-related caries status according the WHO criteria (1997) was completed by recording non-cavitated lesions and the number of sealants in permanent molars. 13 % (1997) and 26 % (1999) of the 8-year old immigrant children had a caries-free mixed dentition; in Germans were recorded 40 % (1997) and 42 % (1999). The caries prevalence in immigrant children (1997: 0.9 DMFS/1999: 1.5 DMFS) was significantly higher compared to the German children (1997: 0.5 DMFS/1999: 0.8 DMFS). Moreover, a significantly lower utilisation of fissure sealants was registered in immigrant children (1997: 0.4/1999: 0.7) compared to their German classmates (1997: 0.5/1999: 1.4). Immigrant children have to be characterized as high caries-risk population. Risk-orientated public dental health programmes involving sealant application seems to be necessary for socio-economically underprivileged children.