Purpose: The aim of the present study was to analyse caries prevalence and fluorosis as well as oral hygiene habits in schoolchildren in north Namibia. Materials and Methods: In 2004, 120 pupils (1st to 8th grade, mean age: 12.3 ± 2.8 years) of the Ombili Primary School were examined by one calibrated clinician for caries (DMFT) according to the World Health Organization criteria, oral hygiene (API) and fluorosis (Dean's index), categorised according to the four different farms where they lived. In addition, samples of drinking water were obtained from the wells of the farms and analysed for quality and mineral content. Results: The pupils at the different farms showed very different caries prevalence (range: 17% to 50% caries-free children) and mean DMFT values (0.96 to 2.67). Oral hygiene measures were not common (60.8% none) or inefficient (mean proximal plaque index: 89.5%) and did not differ greatly between the different farms. The fluoride concentration in drinking water varied considerably (0.28 to 1.06 mg/l). The prevalence of dental fluorosis in all schoolchildren was 65.8%, the Community Fluorosis Index (CFI) was 1.41 and it differed clearly for pupils from the four farms (CFI: 0.5 to 1.65). The DMFT index showed a statistically significant correlation with the fluoride concentration of the drinking water (P 0.05). Conclusions: Based on these results, fluoride concentration in drinking water should be monitored in the future. In parallel, a caries-preventive programme should be developed, as high concentrations of fluoride in drinking water alone do not result in acceptable caries levels. Palabras clave: dental caries, fluorosis, oral hygiene