The name of a 13-year-old girl diagnosed as having idiopathic dilated cardiomyopathy was removed from the cardiac transplant list because a hepatitis-like picture developed that coincided with evidence of decompensation of her cardiac function. On admission, there was only modest evidence of cytolysis (ALT level, 115 U/L) and of cholestasis (bilirubin level, 3.0 mg/dl), but there was severe prolongation of her prothrombin time (28 s). This was followed by elevation of both her transaminases and bilirubin levels. A liver biopsy sample showed extensive necrosis involving both the central and midlobular zones, while periportal areas revealed dilated sinusoids and steatotic multinucleated hepatocytes. A brief improvement of both her liver and her heart was followed by rapid deterioration of the functions of both. Attention is drawn to the relationship between reduced cardiac output and hepatic dysfunction secondary to massive cytolysis.