Given the current promotion of nationwide mandatory public preschool (Desshoff, 2010) there is a need to examine school readiness earlier (Lally, 2010; Snow, 2006; Wilen, 2003). Study one explored which temperament, behavior, and cognitive items teachers of 4-year-old kindergarten (N = 29) rated as highly characteristic versus uncharacteristic of ready preschoolers. Clusters of children who were deemed ready for preschool were identified from this teacher-generated data. Study two examined the degree to which an existing sample of 3-year-olds (N = 662) were socially and emotionally ready for preschool as determined based on similarity to the clusters of ready children created by the teachers in study one. I examined the quality of parent-child interactions, status variables, and earlier temperament as potential predictors of these readiness outcomes. Additionally, for a subset of children (N = 27), I explored the degree of similarity to teacher-chosen ready children as a predictor of cognitive outcomes at about age seven, around the time of first grade. In study one, five ready clusters emerged from the teachers' perspectives. Teachers noted high cognitive skills and following directions as highly characteristic of many of the clusters. Distinguishing the clusters from one another included items pertaining to activity level, sociability, shyness, enthusiasm, and patience. Study two revealed that children who more closely resembled the teacher-selected ready children came from families with higher SES, tended to be female, and were rated by mothers as highly positive at 12 months of age. Additionally, these readiness scores predicted performance on a spatial intelligence task at age 7.