This study introduces the Korean Acute Myocarditis (KAM) score, a predictive model for assessing the likelihood of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) use in acute myocarditis. Analyzing data from 841 patients across seven Korean hospitals, eight clinical parameters were identified as predictors, including cardiac arrest and left ventricular ejection fraction <40%. The KAM score demonstrated excellent discriminant ability, supporting its potential to guide timely interventions and improve patient outcomes.