PURPOSE: We describe and assess the teaching of qualitative methods to postgraduate students using a case study from the Centre of International Child Health, Institute of Child Health, London, which trains mainly health personnel with developing country experience. As the majority of these students are practitioners rather than academics, the teaching focuses on combining theory with practice. We then analyse the results of the assessment of students about this approach and examine lessons learned from this experience. APPROACH: We present the format of a two-week course and the evaluation of this course by the students of the past four years. We describe the process of conducting a learning-by-doing course, giving the day-to-day details of how the course is conducted. We also give examples of how this teaching is done. RESULTS: One indicator of the value of this course is its increasing popularity over the past three years. In 1997-1998, 11 students out of 20 took the course. In 1998-1999, 16 students out of 21 opted for this qualitative module. In 1999-2000, 12 students out of 17 chose this module. DISCUSSION: The lessons learned from this experience include challenges in how to present the teaching within the available time and having realistic expectations concerning course outcomes. We argue that a learning-by-doing approach accomplishes the objectives of having students recognize the value of these methods for health systems research and giving them skills needed to use these methods.