OBJECTIVE To study caries prevalence/severity in 12-year-old children in Latvia and potential risk indicators. METHODS A cross-sectional oral-health national survey of 12-year-old children was conducted in 2016. A nationally representative stratified-cluster probabilistic sample of 2,138 pupils in 92 schools was selected. Children were examined by seven calibrated examiners (kappa inter-examiner, intra-examiner scores of 0.71-0.77, 0.81-0.97, respectively) at school. Enamel-non-cavitated decay (D1), enamel cavitation (D3), dentine cavitation (D5), missing (M) or filled (F) status at the tooth (T)/surface (S) levels were evaluated, and decayed, missing, and filled (DMF) index scores for severity, along with the Significant Caries Index (SiC), were calculated. An associated caries factor questionnaire was completed by participants. RESULTS The prevalence of caries was 98.5% for D1MFT, 79.7% for D3MFT, and 71.9% for D5MFT. The means (standard deviations) for severity were 9.2 (5.3) for D1MFT, 3.3 (3.0) for D3MFT, and 2.4 (2.4) for D5MFT, and 5.6 (2.1) for the SiC. Indicators associated with a lower risk of caries (D5MFT) were irregular dental visits (prevalence odds ratio POR = 0.45, 95% confidence interval (CI): 0.36, 0.56) and irregular use of mouthwashes (POR = 0.73, 95% CI: 0.60, 0.89). CONCLUSIONS We found a high caries prevalence and severity in 12 year-old children in Latvia. Although the WHO target for 2010 (D5MFT ≤ 3) is met, the values for caries prevalence (D5MFT > 0 = 71.9%) and severity (D5MFT = 2.5) in 12-year-old Latvian children are higher than the European averages (D5MFT > 0 = 52%, D5MFT = 1.1).