OBJECTIVES: To explore the judgments of rule-related behaviour by health care professionals and the general public in the UK, against a background in which clinical guidelines and protocols are proliferating. DESIGN: A questionnaire survey was used in which short scenarios describing medical practice were presented to a sample of health care professionals and members of the general public. METHODS: The health care sample consisted of 315 nurses, doctors and midwives from three English National Health Service (NHS) Trusts who volunteered to take part in the study. A stratified sample of members of the general public (N = 350) was recruited via a market research organization. Three types of behaviour (compliance with a protocol, violation of a protocol, and improvization, where no protocol exists) and three types of outcome for the patient (good, bad, poor) were manipulated within nine scenarios. Respondents were asked to make judgments about (1) the inappropriateness of behaviour (2) likelihood that they would take further action and (3) responsibility for the outcome. RESULTS: Findings suggest that the process of care has a greater effect on judgments of the behaviour of health care professionals than does the outcome of that behaviour. This was equally true of the professional and public samples. CONCLUSIONS: The study has both theoretical and practical implications. First, information about a behaviour's relationship to existing rules has a stronger influence than the consequence of the behaviour on attributions of responsibility. Secondly, using clinical protocols as a way of managing risk in the NHS may be counterproductive unless full compliance is achieved.