Abstract: AIM:To explore the risk factors of prolonged mechanical ventilation (MV) following coronary artery bypass grafting in intensive care unit (ICU). METHODS: We conducted a retrospective case/control study for independent risk factors using multivariable logistic regression analysis in 68 patients treated with or without prolonged MV in ICU following coronary artery bypass grafting (CABG). RESULTS: Of the 68 patients, 15 patients were treated with prolonged MV following CABG and 53 cases without prolonged MV; the morbidity rate was 2205%. Univariate analysis showed that risk factors of prolonged MV following CABG were postoperative low cardiac output syndrome, postoperative circulation failure, postoperative renal failure, chronic obstructive pulmonary disease (COPD), diabetes and prolonged postoperative stay in ICU. Compared with those in control patients, the independent risk factors of prolonged MV following CABG were postoperative low cardiac output syndrome (OR 33854, 95% CI: 161-71135), postoperative renal failure (OR 698, 95% CI: 100-4856), and COPD (OR 1235, 95% CI: 109-13935) (P<005). CONCLUSION: The independent risk factors of prolonged MV following CABG are postoperative low cardiac output syndrome, postoperative renal failure and COPD.