The quality of principals is pivotal for quality education. It is only through continuing professional development (CPD) that principals can further enhance professionalism. In this study, both quantitative and qualitative methods were used to analyze the responses of 194 principals and vice-principals. The research findings show that Hong Kong principals are facing challenges posed by ever-changing school environments of the 21st century and educational reforms. Based on this study, implications for future continuing professional development of principals in Hong Kong are speculated.