Ethnographic studies are valuable in studying patient safety. This is a narrative review of four reports of ethnographic studies of patient safety in UK hospitals conducted as part of the Patient Safety Research Programme. Three of these studies were undertaken in operating theatres and one in an A&E Department. The studies found that hospitals were rarely geared towards ensuring perfect performances. The coordination and mobilization of the large number of inter-dependent processes and resources needed to support the achievement of tasks was rarely optimal. This produced significant strain that staff learned to tolerate by developing various compensatory strategies. Teamwork and inter-professional communication did not always function sufficiently well to ensure that basic procedural information was shared or that the required sequence of events was planned. Staff did not always do the right things, for a wide range of different reasons, including contestations about what counted as the right thing. Structures of authority and accountability were not always clear or well-functioning. Patient safety incidents were usually not reported, though there were many different reasons for this. It can be concluded that securing patient safety is hard. There are multiple interacting influences on safety, and solutions need to be based on a sound understanding of the nature of the problems and which approaches are likely to be best suited to resolving them. Some solutions that appear attractive and straightforward are likely to founder. Addressing safety problems requires acknowledgement that patient safety is not simply a technical issue, but a site of organizational and professional politics.