Objective: The aim of this study was to evaluate the efficacy of artificial neural networks (ANN) in predicting intra-abdominal infection in moderately severe (MASP) and severe acute pancreatitis (SAP) compared with that of a logistic regression model (LRM). Methods: Patients suffering from MSAP or SAP from July 2014 to June 2017 in three affiliated hospitals of the Army Medical University in Chongqing, China, were enrolled in this study. A univariate analysis was used to determine the different parameters between patients with and without intra-abdominal infection. Subsequently, these parameters were used to build LRM and ANN. Results: Altogether 263 patients with MSAP or SAP were enrolled in this retrospective study. A total of 16 parameters that differed between patients with and without intra-abdominal infection were used to construct both models. The sensitivity of ANN and LRM was 80.99% (95% confidence interval [CI] 72.63-87.33) and 70.25% (95% CI 61.15-78.04), respectively (P > 0.05), whereas the specificity was 89.44% (95% CI 82.89-93.77) and 77.46% (95% CI 69.54-83.87), respectively (P < 0.05). ANN predicted the risk of intra-abdominal infection better than LRM (area under the receiver operating characteristic curve: 0.923 [0.883-0.952] vs 0.802 [0.749-0.849], P < 0.001). Conclusions: ANN accurately predicted intra-abdominal infection in MSAP and SAPand is an ideal tool for predicting intra-abdominal infection in such patients. Coagulation parameters played an important role in such prediction.intra-abdominal infection, logistic regression, neural network, pancreatitis Male sex, n (%) 165 (62.7) Age, y (median [IQR]) 47 (39-59) History of smoking, n (%) 76 (28.9) History of alcohol consumption, n (%) 85 (32.3) History of hypertension, n (%) 58 (22.1) History of diabetes, n (%) 31 (11.8) Admission to different departments, n (%) Department of Gastroenterology 127 (48.3) Department of Emergency 67 (25.5) Intensive care unit 69 (26.2) Etiology, n (%) Biliary 106 (40.3) Hypertriglyceridemia 92 (35.0) Alcoholic 24 (9.1) Others 41 (15.6) BMI, kg/m 2 (median [IQR]) 25.71 (23.53-27.92) Obese (BMI ≥25 kg/m 2 ), n (%) 146 (55.5) SIRS, n (%) 200 (76.0) Intra-abdominal infection, n (%) 121 (46.0) APACHE II score, median (IQR) 10 (8-13) Abbreviations: APACHE, acute physiology and chronic health evaluation; BMI, body mass index; IQR, interquartile range; SIRS, systemic inflammatory response syndrome.