Mitochondrial encephalomyopathy (ME) is a group of multisystem disorders caused by mitochondrial dysfunction. The clinical manifestations of ME are diverse, complex and the prevalence of the disease is low. However, ME patients generally first visit the mental health department for their complicated psychiatric symptoms. This paper introduced the clinical information, diagnosis and treatment of a case who suffered from mitochondrial encephalomyopathy presenting with lactic acidosis and stroke-like episode （MELAS） with psychiatric complications, and further reviewed the literatures on the clinical features and the diagnostic methods of the disease to raise the clinicians′ awareness and to avoid any misdiagnosis and mistreatment.

Mitochondrial encephalomyopathy (ME) is a group of multisystem disorders caused by mitochondrial dysfunction. The clinical manifestations of ME are diverse, complex and the prevalence of the disease is low. However, ME patients generally first visit the mental health department for their complicated psychiatric symptoms. This paper introduced the clinical information, diagnosis and treatment of a case who suffered from mitochondrial encephalomyopathy presenting with lactic acidosis and stroke-like episode （MELAS） with psychiatric complications, and further reviewed the literatures on the clinical features and the diagnostic methods of the disease to raise the clinicians′ awareness and to avoid any misdiagnosis and mistreatment.