Objectives: Graft patency and completeness of revascularization were analyzed in patients who underwent off-pump minimally invasive coronary artery bypass grafting via left small thoracotomy. Methods: We retrospectively reviewed the invasive angiography findings and clinical data of 186 consecutive patients who underwent off-pump minimally invasive coronary artery bypass grafting via left small thoracotomy. The left internal thoracic artery and saphenous vein were used to bypass two or more of three coronary artery systems: the left anterior descending artery, left circumflex artery, or right coronary artery. Before hospital discharge, invasive angiography was performed to assess graft patency and completeness of revascularization. Clinical variables during hospitalization and follow-up were collected and analyzed. Results: All 186 patients successfully underwent off-pump minimally invasive coronary artery bypass grafting without conversion to sternotomy or assistance of cardiopulmonary bypass. The mean graft number was 2.81 per patient (range, 2–5), and the total number of grafts was 522. The in-hospital mortality rate was 1.6% (3/186). A total of 181 of 186 (97.3%) patients underwent postoperative invasive angiography. Among the 510 grafts assessed by angiography, the total graft patency rate was 96.3% (491/510) [98.3% (171/174) for left internal thoracic artery grafts and 95.2% (318/334) for saphenous vein grafts]. The rate of complete revascularization was 98.8% (510/516) of the total grafts in 180 of 186 (96.8%) patients. Conclusions: Minimally invasive coronary artery bypass grafting using left internal thoracic artery and saphenous vein grafts provides acceptable graft patency and completeness of revascularization for patients with multivessel disease.