Purpose: Caries is a prevalent condition in Saudi Arabia. At present, knowledge regarding caries risk factors in Saudi Arabia is limited. The present study aimed to identify characteristic features of Saudi preschoolers at high risk for caries, using the American Academy of Pediatric Dentistry caries risk assessment tool (CAT ) and to report the most significant caries risk predictors. Materials and Methods: A sample of 407 children aged 4 and 5 years was selected randomly from private and public nursery schools. Their parents answered a questionnaire prepared using the CAT . Each child was examined for the presence of caries and his/her oral hygiene status. Results: According to the CAT , almost all children (89%) were considered to be at high risk. Caries was significantly more prevalent among children attending public than private schools. All CAT variables were significantly related to the presence of caries except general health condition and water fluoridation. Logistic regression analysis showed previous caries experience, enamel demineralisation, and socio-economic status to be the most significant caries risk factors. Conclusion: Most of the Saudi children are considered to be at high risk for caries. Previous caries experience, enamel demineralisation and socioeconomic status are the most significant caries risk predictors. These groups should be targeted for inclusion in caries prevention programmes. Keywords: assessment, caries risk, children, Saudi Arabia