The purpose of this qualitative study was to examine the principal's leadership behaviours of private secondary schools in Hong Kong with respect to the effect of a principal's leadership behaviours on students' enrollment as perceived by teachers and senior teachers. The private secondary schools principals, more than anyone else, have the capacity to create conditions for the teachers, students and parents that influence student enrollment. The literature review has shown evidence on the importance of leadership behaviours of principals in general but there is limited evidence on how teachers perceive the effects of leadership. Therefore, a study on teachers' perceptions of the impact of leadership behaviours on student enrollment was carried out as opposed to a study of the direct impact of leadership on enrollment. The effective leadership behaviours of private secondary school principals were studied from different perspectives of teaching staffs such as (a) principals; (b) senior teachers; and (c) teachers in Hong Kong. Three research questions were answered with data collected using a survey instrument, Leadership Practices Inventory (LPI) (Kouzes & Posner, 2003), and interview instrument, Leader Effectiveness Index (LEI) (Moss et al., 1994). The leadership practices or behaviours rated or ranked high from both the frequency count (Gall et al., 1996) derived from the interview transcript using the Leader Effectiveness Index (Moss et al., 1994) and the questionnaire, Leadership Practices Inventory (Kouzes and Posner, 2003). This study was a crosscase analysis (Creswell, 1998) in a multiple-case study (Yin, 1993), the results were summed up from the number of frequency-count recording. The different leadership ii behaviours of the principals are perceived by the teachers and senior teachers to affect the students' enrollment. Researcher bias is clarified by providing the Researcher's Background (Creswell, 1988; Stake, 1995). Three Leadership practices: (a) Modelling the Way, (b) Encouraging the Heart, and (c) Inspiring the Shared Vision (Kouzes & Posner, 2003) were found to be the principal's leadership behaviours to affect the students' enrollment as perceived by the senior teachers and teachers. Results indicated Modelling the Way may be a key factor or practice to influence the students' enrollment. After analyzing the data, it is shown that the teachers and senior teachers perceived that the key practices of Encouraging the Heart and Inspiring a Shared Vision may also influence the students' enrollment. These findings are also supported by Peyer's (1995) and Marley's (2003) studies conducted on high school students entering the college or university, where modelling the way, encouraging the heart and inspiring the shared vision (with the exception of the leadership practice of "enabling others to act") were found to be explicit behaviours practised by principals. This study has implications for the preparation and in-service training of the principals or administrators who consider the effect of principal's leadership behaviours on students' enrollment. iii