This paper explores the potential and limitations of tandem learning to foster professional development amongst pre-service language (L2) teachers, both from a theoretical and a practical point of view. As such, a review of the literature of the field is first proposed. It suggests that while “tandem learning” is an evenly distributed and rather commonly used pedagogical practice to promote L2 proficiency development and intercultural awareness among learners, this instructional approach paradoxically seems to be unusually relied upon in the professional field to foster skill development. This review then leads to an empirical part in which three tandem and collaborative pre-service teacher training projects are described and analyzed. This part notably focuses on the pedagogical and professional benefits / weaknesses of such an approach to train would-be L2 teachers. We conclude by showing that, while evidence from the literature of / and the field reveals that tandem learning may be a sustainable pedagogical option to consider to work towards achieving professional objectives, the recognition of the potential of this very instructional practice to foster skill development seems more problematic for various actors pertaining to the academic sphere.