In this study, associations were explored between maternal health and lifestyle during pregnancy and in early motherhood, and preschool children’s caries experience. The study was based on the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health and on data from the Public Dental Services. A total of 1348 children were followed from pregnancy to age 5 yr. A clinical dental examination was performed at age 5 yr. Questionnaires were completed by the mothers during pregnancy and in the first 18 months of their child’s life, and as part of the dental examination. Results from the multivariate logistic regression analysis showed that having an obese mother (OR = 2.3, 95% CI: 1.3-4.1), a mother who consumed a diet containing more fat (OR = 1.6, 95% CI: 1.1-2.5) or sugar (OR = 1.5, 95% CI: 1.1-2.3) than recommended, a mother with low education (OR = 1.5, 95% CI: 1.1-2.3) or one or both parents of non-western origin (OR = 5.4, 95% CI: 2.8-10.6) were statistically significant risk indicators for caries experience at age 5 yr. In conclusion, maternal weight and intake of sugar and fat in pregnancy were associated with caries experience in preschool children. These characteristics may enable early referral to the dental services and preventive care to be delivered.