Elevated levels of circulating tumor necrosis factor (TNF)-alpha have been reported in patients with decreased left ventricular ejection fraction. Also, TNF has been reported to depress myocardial contractility. In our previous study, no correlation was found between the plasma level of TNF and clinical parameters in patients with cardiomyopathy. In the present study, we detected elevated levels of circulating TNF-alpha in 5 out of 15 patients with mitral valve disease and in 1 patient with ventricular septal defect whose left ventricular ejection fraction was within the normal range. The levels of TNF-alpha were not correlated with any hemodynamic parameters. Further studies are necessary to clarify the mechanisms of the regulation and effects of TNF-alpha in patients with chronic heart failure.