SummaryCurrent guidance recommends that, in most circumstances, cardiopulmonary resuscitation should be attempted when cardiac arrest occurs during anaesthesia, and when a patient has a pre‐existing ‘do not attempt cardiopulmonary resuscitation’ recommendation, this should be suspended. How this guidance is translated into everyday clinical practice in the UK is currently unknown. Here, as part of the 7th National Audit Project of the Royal College of Anaesthetists, we have: assessed the rates of pre‐operative ‘do not attempt cardiopulmonary resuscitation’ recommendations via an activity survey of all cases undertaken by anaesthetists over four days in each participating site; and analysed our one‐year case registry of peri‐operative cardiac arrests to understand the rates of cardiac arrest in patients who had ‘do not attempt cardiopulmonary resuscitation’ decisions pre‐operatively. In the activity survey, among 20,717 adults (aged > 18 y) undergoing surgery, 595 (3%) had a ‘do not attempt cardiopulmonary resuscitation’ recommendation pre‐operatively, of which less than a third (175, 29%) were suspended. Of the 881 peri‐operative cardiac arrest reports, 54 (6%) patients had a ‘do not attempt cardiopulmonary resuscitation’ recommendation made pre‐operatively and of these 38 (70%) had a clinical frailty scale score ≥ 5. Just under half (25, 46%) of these ‘do not attempt cardiopulmonary resuscitation’ recommendations were formally suspended at the time of anaesthesia and surgery. One in five of these patients with a ‘do not attempt cardiopulmonary resuscitation’ recommendation who had a cardiac arrest survived to leave hospital and of the seven patients with documented modified Rankin Scale scores before and after cardiac arrest, four remained the same and three had worse scores. Very few patients who had a pre‐existing ‘do not attempt cardiopulmonary resuscitation’ recommendation had a peri‐operative cardiac arrest, and when cardiac arrest did occur, return of spontaneous circulation was achieved in 57%, although > 50% of these patients subsequently died before discharge from hospital.