Most students in Health Profession Education courses are new to the world of qualitative research. Faced with the challenge of designing a research project, they are often drawn towards using the questionnaire as a data collection method, commonly assuming that utilising open-ended questions alone constitutes qualitative research design. Designing questionnaires that meet the standards of rigour is challenging, and this common assumption reflects inexperience with and misunderstandings of qualitative ontology, as well as the lack of methodological literature on designing and developing qualitative questionnaires. This paper is written with research supervisors as well as students in mind, as it is aimed to help elucidate the decision-making process and the justification for using a qualitative questionnaire. Drawing upon examples of research conducted by our students, and the wider literature, we demonstrate how qualitative questionnaires can produce rich and meaningful findings when they (1) prioritise qualitative research values, and (2) follow a rigorous design process when the questionnaire is developed. We conclude by offering a simple framework for developing rigorous qualitative questionnaires to those who may consider using this approach.