This study examined the construct and predictive validity of the Essential Skills kindergarten readiness assessment using Exploratory Structural Equation Modeling (ESEM) analysis. Participants included 472 kindergarten children from a local school district. The 5-factor solution obtained from the analysis was compared to the NEGP's five dimensions of kindergarten readiness and results suggested that a physical and motor skills dimension was not present among the factors. However, the Essential Skills kindergarten readiness assessment results suggest that this instrument has predictive validity. One of the factors from the 5-factor solution, which included items that have been established in the literature as important predictors' of children's later achievement, predicted children's end of the year reading and math scores. Concurrent validity was also established in post hoc analyses. These results provide psychometric evidence of predictive and concurrent validity that is important in determining kindergarten readiness and the impact of the community initiatives to increase kindergarten readiness. (author abstract)