We report a Japanese girl affected with a neonatal-onset form of propionic acidaemia (PA). She developed severe metabolic crisis after dehydration at 2 years of age. Bradycardia with complete atrioventricular block responded to haemodiafiltration, but severe cardiac failure was refractory to inotropic treatment. She was diagnosed with acute cardiac dysfunction caused by PA-induced metabolic crisis. Extracorporeal membrane oxygenation (ECMO), a technique for providing mechanical circulatory support, was required. This is the first case report of a PA patient who recovered from a life-threatening metabolic crisis with cardiac failure by ECMO. Cardiac failure may be a cause of death, but it is occasionally an under-recognized complication. Mitochondrial dysfunction in the myocardium due to propionyl-CoA could contribute to the pathomechanism of cardiac complications of PA. We believe that ECMO should be attempted in PA patients with cardiac failure, in addition to haemodiafiltration and other therapeutic measures, because doing so may lead to the recovery of cardiac dysfunction, as was evident in our patient. In conclusion, prompt investigations and management of cardiac complications should be performed immediately during PA-induced metabolic crises.