This study explores the use of portfolios in preparing aspiring principals in Sweden. Forty postgraduate students used portfolios to document course content, reflections, and observations, assessed on themes like leadership, governance, and quality monitoring. Analysis showed strong foundational knowledge but limited development in reflection and practical application. Gender comparisons revealed minimal differences overall, though men reflected more on leadership, while women focused on resource management. The findings highlight portfolios’ value as both assessment and reflective tools, suggesting a need to enhance curriculum elements that support deeper reflection and real-world application in leadership education.