The paper emphasizes the crucial importance of transdisciplinary approach to qualitative research methodology in teaching and learning contexts involving highly stigmatized minority languages. Autoethnography and participatory action research are herein employed as constructive, critical, qualitative methodological procedures relevant to transdisciplinary research on minority languages in applied linguistics. An international project on teaching and learning Romani, QUALIROM, is used as a case study in order to emphasize the fact that mere theoretical knowledge and professional expertise are important but not sufficient for successful implementation and sustainability of outcomes in this field of linguistic research. The analysis suggests that socially engaged minority language learning and teaching projects should be understood as transdisciplinary, collaborative activities that transcend academic boundaries, and in which research participants create a number of interactive contexts within project-oriented communities of practice aimed at reshaping dominant social relations and practices.