Background: There is a need for evidence-based guidelines on how professionals should act following a suicide. In an effort to provide empiric knowledge, we designed a nationwide population-based study including suicide-bereaved parents. Aim: To describe the process from creating hypotheses through interviews to the development of a population-based questionnaire. Method: We used interviews, qualitative analysis and various means of validation to create a study-specific questionnaire to be used in a nonselected nationwide population of suicide-bereaved parents and a control population of nonbereaved (N = 2:1). The Swedish Register of Causes of Death and the Multigeneration Register were used to identify eligible individuals. All presumptive participants received a letter of invitation followed by a personal contact. Results: We developed a questionnaire covering the participants’ perception of participation, their daily living, psychological morbidity, professional actions, and other experiences in immediate connection to the time before and after the suicide. Almost three out of four parents (bereaved = 666, nonbereaved = 377) responded to the questionnaire. Conclusions: By involving parents early in the research process we were able to create a questionnaire that generated a high participation rate in a nationwide population-based study that might help us to answer our hypotheses about bereavement after suicide.