This study investigates teachers' perception of their school leaders, in particular, principals' instructional leadership practices, and tests whether teachers' perception varies across gender. A version of the Hallinger and Murphy [35] Principal Instructional Management Rating Scale (PIMRS) was employed and administered to 389 secondary school teachers in the North-Central geopolitical zone of Nigeria. The descriptive statistics show that there is a reasonable level of engagement of Nigerian school principals with the three dimensions of PIMRS. Specifically, "defining school mission" was rated highest, while "developing a positive school learning climate" has the lowest rating. This means that teachers perceive defining school mission as the greatest instructional leadership behaviour of the principals. Similarly, there appears to be significant differences between male and female teachers' perceptions of principal's instructional leadership behaviour among the principals. This difference occurs for "Managing the instructional program". This study adds to the understanding of instructional leadership practices in Nigeria, which have been rarely explored.