||OBJECTIVES: Purpose of this study was to determine trends in dental caries prevalence and severity amongst South African children in terms of dimensions of time, person and place. METHODOLOGY: During the past 25 years, 3 national surveys were conducted in 1982, 1988/89 and 1999/2002 to determine the prevalence and severity of dental caries in South Africa. Data obtained from these surveys was used to determine trends in dental caries prevalence and severity amongst South African children. In all surveys the WHO methods with regard to dental caries were followed. RESULTS: In terms of variable time, results of the survey show a decrease in the prevalence of dental caries amongst 12-year-old children, from 64.38% (1982), 54.88% (1988/89) to 41.72% (1999/2002) - total of 22.66% over 20 year period or 1.13% per year. A significant decrease (p<0.05) was also observed in the DMFT from 2.54 (1982), 1.73 (1988/89) to 1.17 (1999/2002). The percentage untreated caries in 12-year-old children increased from 70.47% (1982), 72.25% (1988/89) to 75.21% (1999/2002). The South African population comprises of four main population groups, namely: Asians, 2.5%; Blacks, 79%; Coloureds, 8.9% and Whites, 9.5%. Statistically significant decreases (p<0.05) were recorded in the DMFT (1982-2002) in the White, 75.3%; Asian, 64.1%; Black, 49.8%; and Coloured groups, 44.8%. High levels of untreated caries (D) and very low levels of treatment (M and F) were also recorded in all groups. In 2002 in terms of variable place the highest mean dmft/DMFT for 6- and 12-year-olds respectively were recorded in the coastal areas of the Metro Cape (5.1/1.86); followed by Port Elizabeth (3.86/1.37) and Durban (3.42/1.33); and the lowest in the interior - Bloemfontein (2.47/0.73). CONCLUSIONS: 1. Dental caries reduced significantly during the past twenty years. 2. Dental caries is more prevalent and severe amongst Coloured and Black population groups. 3. Higher dental caries prevalence and severity rates were recorded in coastal regions compared to the interior region. 4. Percentage of untreated caries in 12- and 15-year-old children increased, indicating a decrease in dental services rendered to schoolchildren. 5. More than 70% of dental caries in 6-, 12- and 15-year-old children go untreated.