This study is about adolescent leadership. The secondary school in which this study took place has as its motto Learning to Lead. To assist in this task of ‘Learning to Lead’, the author of this research designed and implemented a one semester-long leadership course for the school’s Year 10 cohort. The aim of this study is to examine the leadership understandings of adolescent boys (aged about 15 years) who attended this secondary school course on leadership. In doing so, this study also aims to provide an evaluation of this leadership course. The study specifically addresses two characteristics of boys, first their perception of their competency of their leadership behaviour (the praxis application of leadership), and second, their cognition and knowledge of leadership addressed in the leadership course. Two theoretical frameworks are applied here. First, a modified version of Bass and Avolio’s (2000) Multifactor Leadership Questionnaire (MLQ), was adapted to explore the boys’ levels of perception of their leadership behaviour. Second, Anderson and Krathwohl’s (2001) framework for Learning, Teaching and Assessing, was used to explore the boys’ cognition and knowledge about leadership. Of a population of 158 adolescent Year 10 boys aged about 15 years, 26 boys attended this one semester course on leadership. The two instruments identified were administered to all boys as pretest and posttest instruments over one semester. Leadership behaviour was explored using the modified MLQ. Next, an essay was written by the boys to explore their leadership cognition and knowledge. A paired-samples t-test was conducted to evaluate the impact of the intervention on students’ scores on their behaviour, cognition and knowledge about leadership. The data revealed that the leadership course enhanced the leadership students’ leadership behaviour, cognition and knowledge. First, students developed a perception of their own leadership behaviour, and second, students demonstrated a higher level of thinking of cognition and knowledge of leadership. In practical terms, these findings provide evidence to justify the implementation of the leadership course in teaching the subject of leadership to adolescent boys. The data will be useful to provide guidance for any future modification to a leadership syllabus and evaluation of the Adolescent Leadership Curriculum they studied.