High mortality and extrauterine growth retardation (EUGR) remain serious problems in preterm infants after necrotizing enterocolitis (NEC) surgery. This study investigated the risk factors for mortality and EUGR in preterm infants after NEC surgery. The risk factors were analyzed retrospectively by univariate analysis and multivariate logistic regression analysis in 52 preterm infants, who underwent NEC surgery and were hospitalized in neonatology department of Shanghai Children's Hospital between May 2014 and December 2021. Patients were divided into survival and death groups. Survivors were divided into two groups according to whether EUGR occurred when they achieved full enteral feeding after surgery. The mortality of preterm infants after NEC surgery was 26.9% (14/52). About 55.3% (21/38) of survivors developed postoperative EUGR. (1) Age at surgery, proportion of shock, and intestinal perforation differed significantly between the survival and death groups (p = 0.001, 0.005, and 0.02, respectively). Shock (p = 0.02, odds ratio [OR] = 8.86, 95% confidence interval [CI]: 1.43-55.10) and intestinal perforation (p = 0.03, OR = 6.12, 95% CI: 1.16-32.41) were significant risk factors for death. (2) Compared with the non-EUGR group, proportion of preoperative EUGR, postoperative 1-week calories, and parenteral nutrition time differed significantly in EUGR group (p = 0.001, 0.01, and 0.04, respectively). Preoperative EUGR (p = 0.02, OR = 18.63, 95%CI: 1.77-196.42) was a significant risk factor for postoperative EUGR. Shock and intestinal perforation are significant risk factors for death in preterm infants after NEC surgery. Survivors are prone to EUGR, and preoperative EUGR is a significant risk factor. In addition, adequate caloric intake and achievement of full enteral feeding as soon as possible may be beneficial to improve EUGR of preterm infants after NEC surgery. · Shock and intestinal perforation are risk factors for death in preterm infants after NEC surgery.. · Preoperative EUGR is a risk factor for postoperative EUGR in preterm infants after NEC surgery.. · Active correction of shock and avoiding intestinal perforation may help improve the outcomes..