Purpose: This study aims to be one in a series examining the leadership best practices of school principals as they lead in an accountability- and standards-driven school environment. The lack of research and necessity to find successful practices to improve student achievement highlight the need for this study. Design/methodology/approach: An inductive exploratory study was designed to provide insight into how successful middle school principals facilitate high levels of student achievement. Findings: Common themes of practices enabling the principals to serve effectively in their schools emerged from the conversations and were grouped in the following categories: sharing leadership; facilitating professional development; leading with an instructional orientation; and acting openly and honestly. Originality/value: This research contributes to the field by providing insights into the practices of leaders of successful schools in a high-stakes testing environment. The study provides a framework on which leaders should model their own practices, as well as informing leadership preparation programs areas around which to focus their instructional content.