Learning-related behavioral and academic skills upon kindergarten entry, sometimes referred to as kindergarten readiness, is a construct of growing importance in education, having implications for early learning and eventual achievement. Much of the research on entry skills has been limited to initial status only with inferences drawn about preparedness for school. In this study, I examine the relation among kindergarten entry skills in literacy and mathematics as well as outcomes measured at the end of the kindergarten school year. Two extant datasets were used--learning-related behavioral ratings and academic proficiency skills scores from a fall administration of a statewide kindergarten entry assessment and interim-formative assessment data collected for a subsample of students in the spring of the same academic year. The assessments were analyzed for their factor structures (using both exploratory and confirmatory factor analyses) as well as a hypothesized structural model. Factor analyses tested and confirmed the underlying structure and relations among items and measures included in the state entry assessment. Follow-up structural modeling confirmed the measurement model and concurrently estimated the effects of entry skills on emergent literacy and math skills measured in the spring, while accounting for student-level demographic characteristics. Results indicated that the state's entry assessment measured three distinct skillsets: self-regulation and social-interpersonal learning-related behaviors, and academic proficiency. Importantly, kindergarten entry skills explained a large proportion of variance in spring emergent literacy achievement, beyond that of learning-related behavioral skills and student demographic characteristics. In contrast, these entry skills explained far less variance in spring math achievement. These findings are interpreted in the context of existing theory and recent empirical research. (author abstract)