Children who have caries in their primary teeth in infancy or as toddlers tend to develop additional dental decay in their primary teeth and are more likely to experience caries in their permanent teeth. Information on the prevalence of caries in deciduous teeth enables planners to gauge the burden of disease in children and inform preventive strategies. Objectives: To determine (1) dental caries experience in pre-school children (2) gender distribution of dental caries (3) urban/rural distribution of dental caries (4) to inform dental service recommendations in Tonga. Methods: Six (20%) of the kindergarten schools in the main island of Tongatapu were randomly selected and all the children on the school roll were examined according to the WHO guidelines. Only children aged 3 years (n = 134) and 4 years (n = 249) were included in the study. Results: Caries prevalence and experience for 3 and 4 year olds was 63% (dmft = 3.1) and 74% (dmft = 4.5) respectively. Rural children had a higher carious experience. Ninety four percent of dmf teeth were decayed, and 4% and 47% of them in 3 and 4 year-olds respectively were indicated for extraction. Conclusion: Dental caries in pre-school children is a public health concern. The dental health services should implement preventive measures in kindergarten schools and expand the services to the peripheral clinics in the island to enable more people to receive care.