© The Author(s) 2014. Hemolysis is a common complication of extracorporeal membrane oxygenation (ECMO) support and is associated with increased mortality. Frequent monitoring of markers of hemolysis is performed at ECMO centers. We report two cases of spurious hemolysis caused by hypertriglyceridemia in patients undergoing ECMO support. Critically ill patients, including those receiving ECMO, may be at risk of developing medication-induced hypertriglyceridemia. The interference of lipids with the measurement of plasma free hemoglobin, a marker of hemolysis, should be recognized. Our cases highlight the importance of investigating hypertriglyceridemia as part of the assessment of unexplained hemolysis in patients supported with ECMO.