Objectives The aim was to identify caries risk factors in 1-year-olds predicting dentine caries in 6-year-olds. Materials and methods Caries risk assessment was performed in 804 one-year-olds. Their parents answered a questionnaire, regarding family factors, general health, food habits and oral hygiene. Clinical examinations and caries risk assessments at 1, 3 and 6 years of age were performed. Simple and multiple regression analyses were used for identification of caries-associated factors. Results Caries risk was found in 5% of the 1-year-olds, and 12% of the 3-year-olds. Dentine caries was found in 3% of the 3-year-olds and in 16% of the 6-year-olds. Caries risk assessment was associated with caries at 6 years of age (OR = 5.1,p < .001). Multiple logistic regression analysis found the following variables associated with caries at 6 years of age: Caries in sibling (OR = 2.1,p = .012), Beverage other than water (OR = 2.1,p < .001), Night meal (OR = 1.9,p = .002), Presence of mutans streptococci (MS) (OR = 1.6,p = .033) and Male gender (OR = 1.5,p = .053). An overall caries risk assessment was more reliable than any single caries risk factor. Conclusions Caries risk assessment for 1-year-olds in a region with low caries prevalence has limited accuracy to predict dental caries at 6 years of age. Caries risk often changes over time and should be reassessed on a regularly basis. The presence of MS in 1-year-olds did not increase the prognostic accuracy at 6 years of age.