The purpose of this paper is to present findings from a study of instructional leadership in 20 Icelandic compulsory schools. More specifically, the perceptions of staff concerning supervision of instruction, and the views of principals regarding their role as supervisors of instructional development. Data was collected with questionnaires from staff and interviews with principals. The approach was based on a mixed-methods design. The findings indicate that supervision of instruction differs between the schools. Principals provide for little direct supervision of teachers, however, they provide considerable indirect supervision. The supervision of instruction suggests that collegial supervisory emphasis is considerable in most of the schools. The collegial model, however, emphasizes systematic collection of data on what happens in classrooms, an important element that is largely neglected in the Icelandic schools.