Objective:To explore the role and safety of endomyocardial biopsy (EMB) in the diagnosis of pediatric myocardial disease.Methods:Demographic, clinical and histopathological data of all children receiving EMB in Shanghai Children′s Medical Center, Shanghai Jiaotong University School of Medicine between January 2016 and August 2020 were collected.The pathological results and the procedure-related complications were retrospectively analyzed.Results:A total of 22 patients with the mean age of (10.2±3.1) years underwent EMB.Among them, 13 cases (59.1%) underwent right ventricular EMB, 5 cases (22.7%) underwent left ventricular EMB, and 4 cases (18.2%) underwent biventricular EMB.Among the 12 patients with clinically suspected myocarditis or unexplained heart failure, 4 cases were diagnosed with lymphocytic myocarditis, 2 cases were dilated cardiomyopathy, and 1 case was inflammatory cardiomyopathy.Seven patients presented ventricular diastolic dysfunction, including 6 cases of restrictive cardiomyopathy and 1 of constrictive pericarditis.Three patients exhibited hypertrophic cardiomyopathy with pre-excitation syndrome, involving 2 cases were diagnosed with glycogen storage cardiomyopathy.EMB was successfully performed in all patients.No patient died, and procedure-related complications were not reported.Conclusions:EMB assists the diagnosis and treatment of pediatric patients with selected myocardial disease, which is relatively safe with less complications if performed by experienced interventionalists in qualified pediatric cardiovascular medical centers.