The implementation of the new Statute of the Career Teacher brought about major changes to school organization. One of these changes is the assumption of a new role by teachers, particularly the heads of department, who are now required to assume a more important role not only in the leadership of their departments, but also in supervision since they have become active participants in the evaluation process of their peers.This study aims at describing the beliefs and thoughts and the practices of the language departments heads of two secondary schools in the Azores, in order to get to know their expectations towards their new responsibilities and the obstacles to an effective leadership and supervision that they may be eventually confronted with.We have opted for a descriptive-comparative approach and a mixed methodology combining quantitative and qualitative research. The data were collected through questionnaires and interviews and submitted to statistical and content analysis procedures respectively.The results suggest that there are some differences in the practices of the two heads of departments involved in the study, especially in the way they see their role as supervisors of their peers' pedagogical practice. Specialized (in service) education in fields such as leadership, supervision and evaluation might be, therefore, appropriate, so that the authority of the head of department can be recognized as regards classroom observation, reflection on teachers' performance and subsequent evaluation.