The Intensive Care Foundation, in partnership with the James Lind Alliance, has supported a national project to identify and prioritise unanswered questions about adult intensive care that are important to people who have been critically ill, their families, and the health professionals who care for them. We conducted a secondary analysis to explore differences in priorities determined by different respondent groups in order to identify different groups' perceptions of gaps in knowledge. There were two surveys conducted as part of the original project. Survey 1 comprised a single open question to identify important research topics; survey 2 aimed to prioritise these topics using a 10-point Likert scale. In survey 1, despite clear differences in suggestions amongst the respondent groups, themes of comfort/communication and post-ICU rehabilitation were the within the top 2 suggestions across all groups. Patients and relatives suggested research topics to which they could easily relate, whereas there was a greater breadth of suggestions from clinicians. In survey 2, the number of research priorities that received a mode score of 10 varied from 1 to 36. Patients scored 36 out of the 37 topics with a mode score of 10. All other groups scored topics with more discrimination, with the number of topics with a mode score of 10 ranging from 1 to 20. Differences in the proportions of the representative groups are therefore unlikely to have translated to an impartial conclusion. Clinicians, patients, and family members have jointly identified the research priorities for UK ICM practice.