The aim of this retrospective study was to explore the risk factors and clinical characteristics related to neonatal fulminant necrotizing enterocolitis (NEC). From 1 November 2007 to 31 October 2017, 352 neonates who were diagnosed with NEC (Bell stage ≥ΠB) and admitted to the Children’s Hospital of Chongqing Medical University were enrolled. Among these patients, 112 (31.82%) cases fulfilled the definition of fulminant NEC, and 62.5% (70/112) of fulminant cases presented a poor prognosis. All the survivors in the fulminant NEC group underwent surgery. Those in the fulminant NEC group were more likely to have the following clinical features: sepsis preceding NEC (P<0.001), abdominal distention (P<0.001), bowel sound disappearance (P = 0.001), leukopenia or neutropenia (P<0.001), C-reactive protein (CRP) <10 mg/L (P = 0.003), procalcitonin (PCT) < 2 μg/L (P<0.001), pH ≤7.2 (P<0.001), and radiographic evidence of pneumoperitoneum (P<0.001) or seroperitoneum on ultrasonography (P = 0.017). In conclusion, fulminant NEC is characterized by urgent onset and prompt deterioration, potentially resulting in death. The lack of unique characteristics makes it difficult to recognize by medical caregivers. Close observation, early detection and timely surgical intervention may improve the prognosis.