Background: This study investigated the influence of volatile anesthesia (VA) on major complications and mortality in patients undergoing coronary artery bypass graft surgery (CABG). Methods: This post-hoc analysis included 1586 patients from the MYRIAD trial managed using the same perioperative protocol at a single institution. Patients were randomized to receive either volatile anesthesia (sevoflurane, isoflurane, or desflurane) or total intravenous anesthesia (TIVA). The assessed study outcomes were the rate of complications, including: myocardial infarction, stroke, acute kidney injury, prolonged ventilation (>24 h), receipt of high-dose inotropic support (inotropic score >10), and need for mechanical circulatory support. The duration of intensive care unit (ICU) stay, length of hospitalization, hospital readmission during follow-up, 30-days and 1-year mortality were also analyzed. Results: 1586 patients were enrolled between September 2014–September 2017 and randomly assigned to the volatile anesthesia group (n = 794) and the TIVA group (n = 792). The median patient age was 63 years, with a median ejection fraction of 60%. There were no significant differences in the rates of major complications, duration of ICU stay, and hospitalization between the groups. The median total dose of fentanyl was 12.0 mcg/kg in volatile group and 14.4 mcg/kg in TIVA group (p 0.001). One-year mortality rates were 2.5% (n = 20) and 3.2% (n = 25) in the volatile and TIVA groups, respectively. Two patients were lost at the 30-day and 1-year follow-ups in the volatile group compared to four patients in TIVA group. Regression analysis showed that cardiopulmonary bypass (CPB) duration, fentanyl dose, and baseline serum creatinine level were associated with 30-days mortality, while ejection fraction was associated with 1-year mortality. Conclusions: The use of VA in patients undergoing CABG did not result in a reduction in major complications or mortality compared with TIVA. A higher dose of fentanyl was used in the TIVA group and was associated with an increase in the 30-days mortality. These findings warrant further investigation. Clinical Trial Registration: ClinicalTrials.gov (NCT02105610).