The clinical presentation of acute myocarditis in children may range from asymptomatic to sudden cardiac arrest. This study analyzed the clinical spectrum of acute myocarditis in children to identify factors that could aid primary care physicians to predict the need for extracorporeal membrane oxygenation (ECMO) earlier and consult the pediatric cardiologist promptly. Between October 2011 and September 2016, we retrospectively analyzed 60 patients aged 18 years or younger who were admitted to our pediatric emergency department with a definite diagnosis of acute myocarditis. Data on demographics, presentation, laboratory tests, electrocardiogram and echocardiography findings, treatment modalities, complications, and long-term outcomes were obtained. During the study period, 60 patients (32 male, 28 female; mean age, 8.8 ± 6.32 years) were diagnosed with acute myocarditis. Fever, cough, and chest pain were the most common symptoms (68.3%, 56.7%, and 53.3%, resp.). Arrhythmia and left ventricular ejection fraction (LVEF) < 60%, vomiting, weakness, and seizure were more common in the ECMO group than in the non-ECMO group, with statistical significance (P < 0.05). Female sex, vomiting, weakness, seizure, arrhythmia, and echocardiography showing LVEF < 60% may predict the need for ECMO. Initial serum troponin-I cutoff values greater than 14.21 ng/mL may also indicate the need for ECMO support for children with acute myocarditis.