Excessive ethanol intake is reported in 3% to 40% of patients with idiopathic dilated cardiomyopathy (IDC). In the prevasodilator era, the prognosis was reportedly better in alcoholic than in IDC patients, an advantage limited to abstinent patients. No large series of patients systematically treated with angiotensin-converting enzyme inhibitors has since been described. We analyzed long-term outcome according to alcohol abuse in male patients with IDC. Among 338 men who had been prospectively enrolled in a multicenter registry, 79 (23%) were defined as alcohol abusers and further classified at follow-up as having stopped (AAS) or continued (AAC) abuse. AAC subjects at enrollment reported a higher daily alcohol intake than AAS subjects (178 +/- 113 vs 127 +/- 54 g/day, p = 0.012). During a mean of 59 +/- 35 months, 102 patients died and 45 underwent transplantation. Seven-year transplant-free survival was significantly lower in alcohol abusers (41%) than in patients with IDC (53%, p = 0.026), and significantly lower in AAC subjects (27%) than in either patients with IDC or AAS (45%) (p = 0. 018). Although IDC patients had beneficial changes in left ventricular function at follow-up, only AAS patients had significant improvement in ejection fraction. In this large series of patients treated with angiotensin-converting enzyme inhibitors and prospectively followed up, excessive alcohol intake was found in about one fourth of cases and persistent alcohol abuse correlated with a worse prognosis and function at follow-up.