Myocarditis is an inflammatory disease of the myocardium with a variety of causes. It is potentially reversible, and has been treated successfully with extracorporeal life support (ECLS). With increasing severity, myocarditis results in significant damage to myocardial cells. Dystrophic calcification of the myocardium may occur, serving as a marker of severe damage. At the authors' institution, from July 1990 to January 1992, five patients (four neonates, one 5 year old) with severe myocarditis refractory to medical management were treated with venoarterial ECLS. Three survived (60%) and two died. All patients were female, and their age range was 2 weeks to 5 years. Nonsurvivors had significant myocardial calcification, which was detected by a chest roentgenogram as well as a two-dimensional echocardiogram; the three survivors had no evidence of calcification. The nonsurvivors had minimal recovery of myocardial function and subsequently had their ECLS discontinued at 83 and 169 hours, respectively. The authors conclude that the development of progressive myocardial calcification in conjunction with a lack of recovery of cardiac function is a sign of severe myocardial damage and poor prognosis. Continuation of ECLS in this setting may not be warranted.