BACKGROUND:: Predicting aggressive Crohn’s disease is crucial for determining therapeutic strategies. OBJECTIVE:: We aimed to develop a prognostic model to predict complications leading to surgery within 1 year after diagnosis of Crohn’s disease and to create a nomogram to facilitate clinical decision-making. DESIGN:: This is a retrospective study. SETTING:: This study was conducted from January, 2012, to December, 2016, in a single tertiary inflammatory bowel disease center. PATIENTS:: Patients diagnosed with Crohn’s disease showing B1 behavior according to Montreal classification were included. MAIN OUTCOME MEASURES:: We measured the occurrence of complications that would ultimately lead to surgery, including severe gastrointestinal bleeding (Glasgow-Blatchford score≥6), stenosis, and perforations, confirmed by endoscopy, computed tomography scan, or/and interventional radiology. RESULTS:: The mean follow-up period was 54 months (standard deviation 13 months). Of the 614 eligible patients, 13.5% developed complications leading to surgery. Multivariable logistic regression revealed the independent predictors of early-onset complications to be age (adjusted odds ratio [aOR] per 10-year increase in age=0.4; 95% confidence intervals [95% CI]:0.2-0.8, P=0.004), disease duration (aOR =2.7, 95% CI:1.9-3.8, P<0.001), perianal disease (aOR=16.0, 95% CI: 4.3-59.9, P<0.001), previous surgery (aOR=3.7, 95% CI:1.6-8.6, P=0.003), and extraintestinal manifestations (aOR=7.6, 95% CI: 2.3-24.9, P=0.001). The specificity and sensitivity of the prognostic model were 88.3% (95% CI: 84.8%-91.2%), and 96.6% (95% CI: 88.1%-99.6%), respectively, and the area under the curve was 0.97 (95% CI: 0.95-0.98). This model was validated with good discrimination and excellent calibration using the Hosmer-Lemeshow goodness-of-fit test. A nomogram was created to facilitate clinical bedside practice. LIMITATIONS:: This was a retrospective design and included a small sample size from one center. CONCLUSIONS:: Our validated prognostic model effectively predicted early-onset complications leading to surgery and screened aggressive Crohn’s disease, which will enable physicians to customize therapeutic strategies and monitor disease. See Video Abstract at http://links.lww.com/DCR/B442.Registered at Chinese Clinical Trial Registry (ChiCTR1900025751).