Several studies have focused on the use of stance, particularly in linguistic-based writing research. However, adopting an assertive stance towards the research being reviewed or reported is considered a challenging task for second language writers. Therefore, this study aims at exploring the use of stance in the introductory chapters of EFL Arab postgraduates’ theses employing SFL approach at UniSZA. Data were collected qualitatively based on 22 introductory chapters of doctoral and master theses. The writers’ stance was analysed using the SFL approach, whereas the interviews were analysed manually. The findings showed frequent and different use of finite modal operators, less and different use of adjuncts expressing modalisation and other purposes, and less frequent use of comment adjuncts and subjective, rather than objective orientation of the soft and hard domains. The findings revealed that many participants showed unfamiliarity with the use of modality markers and appropriate social and linguistic conventions. The study concluded that authorial stance is very important to be explicitly taught to postgraduate students to enrich the quality of the academic writing. This study provides significant resources for academic writing instructors, supervisors, and academic writers.