The objective of the present study was to evaluate medium- and long-term results of coronary artery bypass grafting (CABG) in patients with severe left ventricular dysfunction (LVD). Prospective evaluation (clinical follow-up and equilibrium radionuclide angiography scan) of all the patients with severe LVD who underwent CABG from November 1986 to November 1991 at the Tel Aviv Medical Center and were referred to the Post Cardiac Surgery Follow-up Clinic at this institution. Seventy-four consecutive patients (65 men, 9 women, aged 43 to 82 years; mean age, 68.2 years) with left ventricular ejection fraction (LVEF) of 30% or less who underwent isolated CABG (without automatic implantable cardioverter-defibrillator implantation, aneurysmectomy, valve replacement, or other open heart procedures) during a 5-year period and were discharged from hospitalization were prospectively evaluated. Preoperatively, 62% of patients had angina, 65% had congestive heart failure (CHF), and the LVEF ranged from 10 to 30%. The mean number of grafts was 2.98 per patient; the internal mammary artery (IMA) was used in 54 patients. The patients were followed up 4 to 96 months (mean, 64.9 months) post-surgery for survival, clinical status, and left ventricular function. Survival was 96%, 93.2%, 91.9%, 87.8%, 86.5%, 83.8%, and 83.8%, at 1, 2, 3, 4, 5, 6, and 7 years, respectively. Postoperatively, mean angina class improved from 2.9 to 1.4 (p < 0.0001) and mean CHF class improved from 2.7 to 1.8 (p < 0.0001). Mean LVEF improved from 23.5% preoperatively to 35.7% postoperatively (p < 0.0001). The following occur in patients with coronary artery disease and severe LVD undergoing CABG: (1) good medium- and long-term survival is attained; (2) angina class improves; (3) CHF class improves; (4) LVEF objectively improves; and (5). IMA can be used safely as a conduit.