© 2017 British Association of Critical Care Nurses Background: Measuring gastric residual volume (GRV) to guide enteral feeding is a common nursing practice in intensive care units, yet little evidence supports this practice. In addition, this practice has been shown to potentially contribute to inadequate energy delivery in intensive care, which remains a problem in critically ill children. Aims: We aimed to explore paediatric intensive care nurses' decision-making surrounding this practice. Methods: This is a cross-sectional electronic survey in a single mixed general and cardiac surgical PICU in the UK. Results: The response rate was 59% (91/154), and responding nurses were experienced, with a mean PICU experience of 10·5 years (SD 8·09). The three main reasons for stopping or withholding enteral feeds were: the volume of GRV obtained (67%), the appearance of this gastric aspirate (40%) and the overall clinical condition of the child (23%). Most nurses reported checking GRV primarily to determine ‘feed tolerance’ (97%) as well as confirming feeding tube position (94%). Nurses' perceived harms from high GRV were: the risk of pulmonary aspiration (44%), malabsorption of feeds (20%) and the risk of vomiting (19%). GRV was measured frequently in this PICU, with 58% measuring GRV before every feed, 27% measuring every 4 h and 17% measuring every 6 h. The majority of nurses (84%) stated they would be worried or very worried if they could not measure GRV routinely. Conclusions: PICU nurses' decision-making surrounding initiating and withholding enteral feeds and determining ‘feed tolerance’ remains heavily based on GRV. PICU nurses have significant fears around patient harm if they do not measure GRV routinely. Relevance to clinical practice: This nursing practice is likely to be one of the factors that impair the delivery of enteral nutrition in critically ill children, and as such, its validity and usefulness needs to be challenged and studied in future research.