Background: Early childhood caries (ECC) risk factors are suspected to vary between regions with different caries prevalence.Aim: Identify ECC risk factors for 1-year-olds predicting dentin caries at 3 years of age in a region with low caries prevalence.Design: Caries risk was assessed by dental hygienist or dental assistant in 779 one-year-olds. The oral mutans streptococci (MS) score was performed from a tooth surface or (in pre-dentate children) from oral mucosa. A parental questionnaire with questions regarding family factors (siblings with or without caries), general health, food habits (night meals, breastfeeding, other beverage than water), oral hygiene habits and emerged teeth were answered by parents of the 1-year-olds. Dentin caries was assessed when the children were 3-year-olds. Simple and multiple logistic regression analyses were used for identification of caries-associated factors.Results: An increased caries risk was assessed in 4.4% of the 1-year-olds. Dentin caries was found in 2.6% of the 3-year-olds. Caries risk at 1 year was associated with caries at 3 years (OR=6.5, p=.002). Multiple regression analysis found the variables Beverages other than water (OR=7.1, pamp;lt;0.001), Caries in sibling (OR=4.8, p=.002), High level of MS (score 2-3) (OR=3.4, p=.03) and Night meal (OR=3.0, p=.03) to be associated with caries. The single variables Beverage other than water between meals and Caries in sibling were more reliable than Caries risk assessed performed by dental personnel.Conclusions: Behavioural, family and microbial factors are important when assessing caries risk among 1-year-olds in a region with low caries experience.