OBJECTIVE This study assessed the development of caries in preschool children over two years according to baseline caries pattern. METHODS Connecticut Head Start children (n = 142, mean age = 3.8 years) were examined for dental caries at baseline (spring 1991) and once annually for two years. Children were categorized at baseline as caries-free, having pit and fissure (PF) caries, or having maxillary anterior (MA) caries. RESULTS After two years, children who presented at baseline with MA or PF caries had a mean posterior dmfs of greater than seven and four times, respectively, that of children who were caries-free at baseline. When dental caries of the primary dentition was categorized by specific posterior patterns (i.e., posterior proximal [PP] and buccal/lingual [BL]), change in dmfs for the PP and BL patterns in the group that presented with pit/fissure caries at baseline were nearly four and three times greater, respectively, than for those in the caries-free group. The group that presented with maxillary anterior caries at baseline had PP and BL caries increments eight times those of children who began caries-free. CONCLUSIONS Dental caries presentation in 3- to 4-year-old children can identify those children and tooth surfaces that will be at the greatest risk for future caries development.