OBJECTIVE To compare postoperative and long-term results (angina, myocardial and cerebrovascular events and coronary re-intervention) using single versus bilateral internal mammary arteries (SIMA vs. BIMA) in the setting of off-pump revascularisation (OPCAB) within a single-surgeon practice. METHODS Retrospective analysis of all isolated OPCAB performed in our institution by a single surgeon in the last 12 years.Two groups were analysed: SIMA (n = 681) and BIMA (n = 342). A propensity score matching was performed to compare the groups, reducing the sample to 684 patients.Follow-up (mean 6.5 ± 3.5 years) was done by telephone interviews or clinical visits, registering also late mortality and coronary re-intervention. Outcomes were compared to literature. RESULTS Demographic characteristics differed between groups, with BIMA offered predominantly to non-diabetic younger males (mean 59.4 years) with less comorbidity. In-hospital mortality was 2% for the SIMA group and 1% for BIMA (p = 0.18). Long-term mortality was also higher for the SIMA group (2% vs. 1% at 1 year, p = 0.22 and 16% vs. 5% at 5 years, p < 0.001). Sternal wound infection was similar in both groups (2-3%). Long-term follow-up revealed good freedom from angina (94%) with low rates of neurological and myocardial events (3%) or need for repeated revascularisation (3%) in both groups. CONCLUSION BIMA offers long-term survival benefit with similar postoperative complications. Rates of deep sternal wound infection were comparable between the two groups.Excellent outcomes can be achieved with OPCAB BIMA in real world practice with adequate patient selection.