Outcome in 81 pediatric patients with dilated cardiomyopathy was reviewed to assess whether treatment with angiotensin-converting enzyme (ACE) inhibitors affected survival. Age at onset was 3.6 +/- 0.6 years. Twenty-seven children (group 1) were treated with ACE inhibitors. Conventional therapy was used in the remaining 54 patients (group 2). There were no significant differences between the two groups in age at onset, left ventricular shortening fraction, left ventricular end-diastolic pressure, or mean pulmonary artery pressure. Patients treated with ACE inhibitors had a significantly better survival during the first year (p < 0.05) with continuation of this trend throughout the second year (p = 0.06). Beyond 2 years there was a tendency toward better survival in ACE inhibitor-treated patients, but the differences were no longer significant (p = 0.14). These data, along with observations in adult patients with chronic cardiac failure, indicate that converting enzyme inhibitors have a beneficial effect on prolonging survival of infants and children with severe left ventricular dysfunction from dilated cardiomyopathy.