Objective To analyze the clinical characteristics of fulminant myocarditis (FM) in children, and to provide references for the clinical decision-making of pediatricians. Methods The clinical data of children with FM who were hospitalized in the pediatric intensive care unit (PICU) from October 2019 to October 2022 were retrospectively analyzed. Results Twelve children with FM (5 boys and 7 girls) were included. The median age was 10.0 (5.6-12.6) years, the median time from onset of disease to treatment was 5.0 (3.0-6.0) days, and the median length of hospital stay was 12.0 (11.0-16.8) days. Twelve patients had no specific symptoms, 11 had circulatory symptoms, and 1 had gastrointestinal symptoms only. The onset symptoms were as follows: 8 children had digestive symptoms, 5 children had neurological symptoms, 2 children had both digestive and neurological symptoms, and 1 child had respiratory symptoms. The levels of myocardial troponinⅠ(cTnⅠ), brain natriuretic peptide (BNP) and lactate dehydrogenase (LDH) were elevated in all children. The median cTnⅠ level was 5.5 (1.4-12.6) ng/L, the median BNP level was 11630.0 (6440.0-28152.0) pg/mL, and the median LDH level was 642.0 (465.5-1194.3) U/L. The myocardial troponin T (cTnT) level was elevated in 11 patients (1 child undetected), and the median cTnT level was 1.2 (0.3-3.9) ng/L. The levels of serum creatine kinase (CK) and creatine kinase isoenzyme (CK-MB) were elevated in 9 patients, the median CK level was 348.5 (99.3-674.8) U/L, and the median CK-MB level was 35.4 (24.5-97.2) U/L. The D-dimer levels were elevated in 10 patients, and the median D-dimer level was 1.7 (0.6-3.3) mg/L. Electrocardiogram and echocardiography were abnormal in all patients after admission. Three patients were treated with extracorporeal membrane oxygenation (ECMO). Ten patients (83.3%) were discharged after improvement, and 2 died. Conclusions The onset symptoms of FM in children are atypical. The positive rates of myocardial enzyme, electrocardiogram and echocardiography were high. ECMO is an effective method to treat FM.