The role of the school principal, as defined in the Australian Professional Standard for Principals, is complex and diverse. Increasing principal autonomy and accountability has broadened the responsibilities of school leaders, making their role more challenging. Developing aspiring principals’ knowledge, skills and abilities is more important than ever. But how is this achieved? How should training programs for school principals be developed? This is the challenge facing education systems. This report draws on best-practice leadership development in education and other sectors to develop key considerations for the design of principal preparation programs to help systems meet this challenge.