In patients with idiopathic noncirrhotic portal hypertension (INCPH), data on morbi-mortality of abdominal surgery are scarce We retrospectively analyzed the charts of patients with INCPH undergoing abdominal surgery within the VALDIG network. Forty-four patients with biopsy-proven INCPH were included. Twenty-five (57%) patients had ≥1 extrahepatic conditions related with INCPH and 16 (36%) had a history of ascites. Forty-five procedures were performed, including 30 minor and 15 major. Nine (20%) patients had ≥1 Dindo-Clavien grade ≥3 complication within 1 month after surgery. Sixteen (33%) patients had ≥1 portal hypertension related complication within 3 months after surgery. Extrahepatic conditions related with INCPH (p=0.03) and history of ascites (p=0.02) were associated with portal hypertension related complications within 3 months after surgery. Splenectomy was associated with development of portal vein thrombosis after surgery (p=0.01). Four (9%) patients died within 6 months after surgery. Six-month cumulative risk of death was higher in patients with serum creatinine ≥100 μmol/L at surgery (33%, vs. 0%, p<0.001). An unfavorable outcome (i.e. either liver or surgical complication or death) occurred in 22 (50%) patients and was associated with presence of extra-hepatic conditions related with INCPH, history of ascites and serum creatinine ≥100 μmol/L: Five percent of the patients with none of these features had an unfavorable outcome, vs. 32% and 64% when one or ≥ 2 features were present, respectively. Portal decompression procedures prior to surgery (n=10) were not associated with post-operative outcome. CONCLUSION: Patients with INCPH are at high-risk of major surgical and portal hypertension related complications when they harbor extrahepatic conditions related with INCPH, history of ascites or increased serum creatinine. This article is protected by copyright. All rights reserved.