School systems have access to more data than ever before, but most teachers and school leaders lack the skills to use the data for student and school improvement. Current attempts to use data have lacked depth and have been more focused on accountability and meeting state and federal requirements than on systematically investigating the factors that support and hinder the teaching and learning process. As a result, the potential benefits of data usage have not been realized. This commentary examines the critical issues facing school leaders concerning data-informed decision-making based on existing research and firsthand experience working with school principals.