BACKGROUND:Critically ill morbidly obese patients pose considerable healthcare delivery and resource utilisation challenges. However little is known about the care of these patients in intensive care. OBJECTIVE:To explore medical and nursing practices and attitudes in intensive care when caring for critically ill morbidly obese patients. METHODS:A focused ethnographic approach was adopted. Participant observation of care practices and interviews with intensive care doctors and nurses were undertaken over a four month period. Qualitative analysis was conducted using constant comparison. SETTING:An 18 bedded tertiary intensive care unit in New Zealand. PARTICIPANTS:Sixty-seven intensive care nurses and 13 intensive care doctors involved with the care and management of seven critically ill patients with a body mass index ≥40kg/m2. FINDINGS:Morbidly obese patients present significant physical and language challenges for intensive care practice. The physical shape of morbidly obese patients did not appropriately fit the different equipment used. Staff used specific knowledge of the patient's body size and shape to adapt care practices and keep patients safe and comfortable. There were also specific language challenges where staff expressed concern about what words were most appropriate to use to describe body mass when in the presence of morbidly obese patients. CONCLUSIONS:Bariatric care pathways need to be developed that use more suitable body measurements to inform the use of bariatric equipment. Intensive care staff need to engage in debate about what is acceptable, respectful, and appropriate language in the delivery of bariatric patient care.