The quality of school principals is of paramount importance for quality education. This article examines the leadership capacities of a group of 228 aspiring principals who participated in a training programme for the principalship in four cohorts. A questionnaire consisting of 24 questions in six core areas of leadership was constructed and distributed to the aspirants one month before the commencement of the training programme. The purpose of the study can contribute to a better understanding of the aspirants' leadership capacities in general and the refinement of the training programme for aspirants in particular. The findings indicate that the aspirants seemed to feel more competent in the leadership area of "teacher professional growth and development" than they did with regard to "quality assurance and accountability", "learning, teaching and curriculum", "strategic direction and policy environment", "external communication and connection to the outside world", and finally "staff and resources management". (Contains 5 tables.)