Abstract: 　Objective　To explore the clinical presentation, diagnosis, treatment, and outcome of the Barth syndrome (BTHS). Methods　Clinical data were collected and analyzed from 3 patients with confirmed genetic diagnosis of BTHS from June 2013 to October 2014. Results　All of the 3 patients were males and two of them were twins. The main clinical manifestations of the 3 patients were cardiomyopathy and heart failure, accompanied by different degrees of trabeculations of the left ventricle. Two of them were diagnosed of left ventricular noncompaction (LVNC). All of the 3 patients presented with motor retardation, muscle weakness, growth delay and significantly increased urinary excretion of 3-methylglutaconic acid (3-MGC). One patient was found to have neutropenia. All 3 patients had TAZ gene mutations which included a novel missense mutation (c.527A>G, p.H176R) detected in the twins and a known nonsense mutation (c.367C>T, p.R123X) identified in the other patient. All of the mutations were inherited from their mothers. During the follow-up, the twins died at 7 months old and 7.5 months old respectively. The other patient was still alive. Conclusion　BTHS is one of the causes of cardiomyopathy in children. In the male patients who presented with muscle weakness, neutropenia, and increased urinary excretion of 3-MGC, especially in those combined with LVNC, BTHS should be screened.