Objective To compare the clinical effects of coronary artery bypass grafting (CABG) via the left anterior small thoracotomy (LAST) versus lower-end sternal splitting (LESS) approach in the treatment of coronary heart disease. Methods The patients who underwent LAST CABG in Tianjin Chest Hospital from October 2015 to December 2020 were allocated to an observation group (LAST group), and the patients who underwent LESS CABG at the same period were allocated to a LESS group. Propensity score matching method was applied with a ratio of 1∶1. The baseline data, perioperative data and grafts data were compared between the two groups after matching. Results Before matching, there were 110 patients in the LAST group, and 206 patients in the LESS group. After matching, there were 110 patients in each group. In the LAST group, there were 83 males and 27 females with an average age of 60.6±8.3 years. In the LESS group, there were 80 males and 30 females with an average age of 61.0±9.6 years. There was no statistical difference in baseline data between the two groups after matching (P>0.05). The hospital stay time (t=2.255, P=0.025) and ventilator using time (t=−2.229, P=0.027) in the LAST group were significantly shorter than those in the LESS group. There were no statistical differences between the two groups in the postoperative hospital stay time, ICU stay time, postoperative left ventricular ejection fraction, postoperative left ventricular end-diastolic diameter, average number of grafts, secondary intubation, secondary thoracotomy, postoperative wound infection, sternal complications, postoperative atrial fibrillation, postoperative pulmonary infection or main adverse cardiovascular and cerebrovascular events (P>0.05). There was no statistical difference in the distribution of target vessels in the anterior descending branch, diagonal branch or posterior descending branch between the two groups (P>0.05). The grafts of the LAST group were significantly more than those of the LESS group in the area of obtuse marginal branch and posterior ventricular branch, and the grafts of the LESS group were significantly more than those of the LAST group in the area of right coronary artery (P<0.05). Postoperative computerized tomography angiography indicated that 1 patient in the LAST group had obtuse marginal branch vein bridge vessel occlusion, and the bridge vessels in the other patients were unobstructed. Conclusion Minimally invasive CABG via both LAST and LESS approaches is safe and effective. LAST approach can achieve complete revascularization for multi-vessel lesions, and it is safe and reliable, with the advantages of less trauma and aesthetic appearance. However, it requires a certain learning curve of surgical techniques and certain surgical indications.