The leadership and pedagogical supervision process in teacher education is a crucial issue for the training pedagogical quality and teachers’ professional development. The relationship that is necessary to establish between the Higher Education Institution and the Cooperating Schools where the supervised pedagogical practice is carried out is crucial. In this study we analyze this process of shared leadership and supervision, understanding this relationship from a perspective of effective collaboration, reflexivity and sharing of practices between various contributors – the preservice teacher, the university professor and the mentor teacher. Based on this premise, we shall analyze the importance of leadership in an educational context and the role of supervision for the improvement of organizational and teaching-learning situations and experiences. The aim of this study is to promote autonomy and shared interaction, contributing to professional development and knowledge co-construction. In methodological terms, this is a case study, within the scope of the Master in Teaching of Economics and Accounting at the Institute of Education, University of Lisbon, the only master’s degree in Portugal that provides a professional qualification for teaching in secondary education in the area of Economics and Accounting. This study intends to obtain a characterization of the leadership and supervision process developed, to reflect on appropriate leadership theories in educational context and to outline the main functions of the mentor teacher as a fundamental part of the collaborative supervision process, framed in the current model of teacher training in Portugal.