BACKGROUND: Extracorporeal membrane oxygenation (ECMO) induces coagulation disorders increasing the risk of bleeding during invasive procedures. We aimed to describe the outcomes of critically ill ECMO patients undergoing emergency abdominal surgery compared to non-ECMO patients. STUDY DESIGN: This is a retrospective case-matched single-center study with propensity score analysis in a tertiary ICU. All patients who underwent abdominal surgery were included. RESULTS: From 2006 to 2014, 77 patients admitted in our ICU underwent emergency abdominal surgery, 35 were on ECMO. Surgery indications were comparable for ECMO and non-ECMO patients: mostly intestinal ischemia (42%) and cholecystectomy (25%). Postoperative bleeding was significantly more frequent in ECMO group versus non-ECMO: 77% versus 40% transfused, with medians of 13 (6-22) versus 3 (0-5) packed red blood cell; 9 (3-17) versus 0 (0-4) fresh frozen plasma and 12 (3-22) versus 0 (0-8) platelet units (p < 0.001 for all items). Reintervention for hemorrhage was required in 20% versus 2%, respectively, p = 0.02. At multivariable analysis, ECMO was strongly associated with bleeding (OR, 5.6 [95% CI, 2.0-15.4]; p = 0.001). ICU mortality was higher for ECMO-treated patients (69% vs. 33%; p = 0.003), but perioperative mortality remained comparable between groups (11% vs. 12%, NS). Propensity score-matched analysis confirmed more frequent and severe bleeding in ECMO patients. CONCLUSIONS: Abdominal surgery procedures on ECMO-treated patients are associated with a higher risk of hemorrhage compared to non-ECMO ICU patients. Further studies are needed to optimize ECMO patient management during such interventions.