A total of 138 patients with idiopathic dilated cardiomyopathy were assessed and followed-up between July 1973 and October 1985 in order to evaluate prognostic risk indicators. Of these 102 were male and 36 were female with a mean age of 49.1 years. Each patient underwent physical examination, electrocardiography, echocardiography, cardiac catheterization and coronary angiography. The mortality rate was low for the first 3 years (respectively 8, 12.5 and 20%) while it was 57.5 at the end of the 5-year follow-up period. Univariate analysis at the time of the diagnosis revealed that five factors were predictive of the clinical course at the end of the fifth year: the NYHA functional class IV (p less than 0.0001); LV ejection fraction less than 0.30 (p less than 0.01); left ventricular failure, bi-ventricular failure and left ventricular end-diastolic pressure greater than 20 mmHg (p less than 0.05). Multivariate analysis was used to determine which combination of factors could most accurately predict survival. The most important prognostic factor was again the IV NYHA functional class (p less than 0.01) and, to a lesser degree, left ventricular end-diastolic pressure (p less than 0.05). The present study underlines that the survival rate of patients with dilated cardiomyopathy depends upon the selection of patients. This can explain the low 3-year mortality found in our patients. The NYHA functional class may be a useful practical guide for cardiac transplantation.