Developmentally appropriate, psychometrically sound instruments are needed to assess young children and evaluate learning programs. In the United States, little guidance exists on the development and use of large-scale assessments that cover the broad range of skills that encompass young children's development. In 2005 and 2006, the State of Connecticut passed legislation requiring the implementation of a statewide developmentally appropriate assessment that "measures a child's level of preparedness for kindergarten." In response to this legislation, the Connecticut State Department of Education developed a Kindergarten Entrance Inventory. The Inventory was designed to provide a statewide snapshot of the skills that children demonstrate, based on teachers' observations, at the beginning of the kindergarten year. This article investigates teacher ratings of children's skills at kindergarten entry in one large urban district using a series of exploratory and confirmatory factor analyses. Analyses indicate that readiness evaluations should address the following skills: expressive language, receptive language, responses to stories, familiarity with books, familiarity with letters, emergent writing, counting, shapes and patterns, measurement, fine motor skills, gross motor skills, conflict resolution, social engagement, engagement with self-selected activities, and creative skills. (Contains 5 tables.)