The article presents a reflection on the challenges of studying judicial working conditions and its impact on the judicial professionals’ health and well-being, with a mixed-methods design and technique. It discusses the work developed on the project “QUALIS” focused on the working conditions of Portuguese judges, public prosecutors and court clerks. This contribution will contextualize the research problem and the “QUALIS” approach and share two main methodological challenges: selecting and building the data collection methods, questionnaire and interviews; and analysing the mixed-methods data results. The questionnaire and interviews were used to gather information about judicial professionals’ perceptions of working conditions in courts (e.g. physical environment, work intensity and social environment), as well as work-family conflict and the impact on health and well-being. The article highlights the importance of adapting the instruments to judicial professionals’ specificities and interests and opens the discussion on the instrument’s results apparent mismatch.