Aim Improved survival rates for premature infants have also increased the population at risk of necrotising enterocolitis (NEC). This study evaluated the outcomes of surgically treated NEC and identified risk factors for mortality, intestinal failure (IF) and IF associated liver disease (IFALD). Methods This was a retrospective observational study of 131 infants with surgically treated NEC from 1976 to 2016 in a Swedish tertiary referral centre: 20 in 1976-1996, 33 in 1997-2006 and 78 in 2007-2016. Data were extracted from medical records, and the Cox regression model was used to identify risk factors. Results When the first and last periods were compared, they showed decreases in both gestational age, from 30 to 26 weeks, and mortality rates, from 45% to 29%. IF was found in 67 patients (56%), IFALD in 41 patients (34%) and short bowel syndrome (SBS) in 13 (19%). The incidence of IF was high, even in infants without SBS. Low gestational age was an independent risk factor for mortality. No risk factors were identified for IF or IFALD. Conclusion Survival rates for NEC improved from 1976-2016, despite a decrease in gestational age. Clinicians should be particularly aware of the risk of infants without SBS developing IF.