Abstract: AIM: To develop and compare the efficacy of a modified vs. conventional rat model of acute myocardial ischemia/reperfusion. METHODS: Sixty Sprague Dawley (SD) rats were randomly divided into two groups: a modified group (respiratory mask support and short-time chest opening) and a conventional group (tracheal intubation and long-time chest opening). Surgical time, surgical success rate, survival rate, and infarct size were investigated, and the postoperative survival rate of the rats was observed. RESULTS: During the perioperative period, the surgical success rate was higher in the modified model ［(93.3±4.6)% vs. (72.4±8.4)%, P<0.05］. Chest-opening time was shorter in the modified group vs. the conventional model ［(6.5±2.0) min vs. (44.9±2.7) min, P<0.01］. Postoperative resumption of normal behaviors and activities was quicker in the modified group, with a statistically significant higher survival rate compared with that in the conventional group (82.83% vs. 58.3%, P<0.001). Triphenyltetrazolium chloride staining showed no significant difference in infarct size between groups ［(33.5±2.2)% vs. (35.0±3.0)%］. CONCLUSION: The modified method offers the advantages of simplicity, efficiency and independent operation, which enhances the success rate of establishing the acute rat myocardial ischemia/reperfusion model.