Parenteral nutrition transformed the prognosis for infants and children with intestinal failure. Soon after its introduction into clinical care 50 years ago, parenteral nutrition was also rapidly adopted for use in the preterm infant, where immaturity of gastrointestinal motor function precluded enteral feeding. Preterm infants subsequently became the single largest group of patients to be fed in this way. Although the development of scientific knowledge and the lessons of clinical experience have reduced the risk of complications, some of the problems and difficulties associated with this form of nutritional support remain challenging. These include central venous catheter-related sepsis, thrombosis, liver disease, bone disease and metabolic disturbance. In an initiative to promote best practice, guidelines on parenteral nutrition were first published by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition and collaborating organisations in 2005. These were constructed following a thorough review of the scientific literature, allowing a series of evidence-based recommendations to be made. The exercise was repeated just over 10 years later and updated guidelines published in 2018. This review summarises key elements from the new guideline, with a focus on what has changed since 2005.