This study explores the impact of instructor practices on transformative learning in shortterm study abroad (STSA) programmes. Combining statistical analysis of competencies with critical reflection reveals the nuanced role of instructors in fostering Civic Action, Perspectivetaking, Cultural Awareness, and more. Results from t-tests highlight significant improvements, emphasising the effectiveness of well-designed STSA initiatives. The paper identifies key practices, including pre-trip preparation, in-country engagement, and reflective writing, as instrumental in enhancing competencies. While acknowledging study limitations, the findings underscore the transformative potential of STSA when coupled with strategic instructor interventions. This research contributes to the ongoing discourse on experiential learning and informs educators and policymakers on optimising STSA for comprehensive student development.