Although the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors in patients with ventricular systolic dysfunction are well documented, historically, a large proportion of patients have not received optimal therapy. Published studies to describe the trends in ACE inhibitor utilization and determinants of their use were reviewed. In recent years the number of patients treated with ACE inhibitors has increased; however, a relatively small proportion of these patients received adequate therapeutic dosages. Attention to factors that impair proper use of these agents is essential to realize improved outcomes in these patients.