In 1993, a cross-sectional oral health survey of 739 randomly selected seven- to 12-year-old Canadian school children was conducted in Forteau (Labrador), Roddickton (northern Newfoundland), and Flower's Cove (northern Newfoundland) to determine the prevalence of dental caries and fluorosis. Children in grades two through six (n = 838) were selected to participate in the survey, which achieved a response rate of 88.2 per cent. Caries prevalence was estimated using modified World Health Organization (WHO) criteria (non-cavitated carious pits and fissures were coded separately from cavitated carious lesions). Fluorosis was measured using the Tooth Surface Index of Fluorosis (TSIF). In-school examinations were carried out by three dentists using portable equipment. There was a significantly higher percentage of caries-free children in Forteau (17.6 per cent) than in Roddickton (7.1 per cent) or Flower's Cove (8.3 per cent). Less than 20 per cent of the children surveyed in all regions had fluorosis. When fluorosis was present, it was mostly of the "very mild" type. Children from Forteau had a significantly lower mean number of decayed permanent teeth than children from the two other regions (1.6 in Forteau, versus 2.7 in Roddickton and 3.4 in Flower's Cove). The mean number of sealed teeth was significantly higher in Forteau children (mean = 1.1) compared with children from Roddickton (mean = 0.3) and Flower's Cove (mean = 0.03). In Forteau children, the F/DMFS2 (non-cavitated carious lesions excluded) ratio was 57 per cent, compared to a ratio of 29 per cent in children from Roddickton and 25 per cent in children from Flower's Cove. Similarly, the mean number of non-cavitated carious pits and fissures were higher than cavitated tooth surfaces by a ratio of 1.5 to 1. The risk markers significantly associated with lower DMFS scores were the number of sealants, lower grade level, college or university education of parents, and residence in Forteau. However, dental caries is endemic in the region and there is a clear need for an accessible school- and community-based oral health promotion and treatment program. In conclusion, this survey found that sealants are effective in preventing dental caries.