Background: It is not yet settled whether there is an add-on benefit to coronary artery bypass grafting (CABG) of treatment with an angiotensin-converting enzyme (ACE) inhibitor in patients with only moderately impaired left ventricular function and no clinically recognized heart failure. Objective: To assess whether treatment with an ACE inhibitor improves the clinical outcome and left ventricular remodeling after CABG in such intermediate-risk patients. Methods: At a median of 7 days after CABG, 130 patients with a mean left ventricular ejection fraction (LVEF) of 0.42 (SD 0.06), no recent myocardial infarction and no clinically recognized heart failure were randomized to and commenced treatment with ramipril or placebo (target dose 10 mg) and were subsequently followed for a median of 33 months (range 12–46 months). A preoperative and at least one postoperative echocardiogram were obtained in 108 patients. Results: Ramipril reduced the incidence of the triple composite end point of cardiac death, acute myocardial infarction and development of clinical heart failure (relative risk 0.41, 95% confidence interval 0.18–0.97; p = 0.045). Ramipril also had a beneficial effect on the change in left ventricular end-systolic volume index from preoperatively (ramipril group –0.22 ml/m2 and placebo group +4.90 ml/m2, p = 0.036), but did not reduce the incidence of recurrent angina. Multivariate analyses revealed that the beneficial effects with ramipril were independent of baseline variables including the LVEF. Patients who suffered the triple composite end point had a lower health-related quality of life score, dyspnea-fatigue rating and exercise capacity during the study period. Conclusion: These results suggest an add-on benefit of ramipril for major cardiac events and remodeling after CABG in intermediate-risk patients and therefore may justify recommendation of treatment with ramipril after CABG in such patients.