Significant attention is currently focused on ensuring that children are enrolled in preschool. However, regular attendance is also critically important. Children with better preschool attendance have higher kindergarten readiness scores, this is especially true for students entering with low skills. Unfortunately, many preschool-aged children are chronically absent. They often miss preschool for health reasons, but many families also face a range of logistical obstacles in getting their children to preschool every day. This report outlines some key findings from this study such as: (1) the extent of absenteeism among preschool students, (2) a comparison of absenteeism among students in kindergarten through third grade, and (3) examining the relationship between preschool absenteeism and learning outcomes, both during preschool and in second grade. The report also explores reasons why preschool students miss school. This report includes Appendices: (A) Data Sources, Description of Samples, and Analytic Methods, (B) Development of the Kindergarten Readiness Tool Rasch Subscales, (C) Relationship between Preschool Attendance and Growth on Woodcock-Johnson III, Endnotes and About the Authors.