Purpose: The feasibility of using bilateral internal thoracic artery (BITA) grafts for coronary artery bypass grafting (CABG) in octogenarians is not clear. This study aimed to compare outcomes between use of BITA and single internal thoracic artery (SITA) grafts in octogenarians undergoing isolated CABG.Methods: Isolated CABG was performed in 1,566 patients at the Sakakibara Heart Institute between September 2004 and December 2012. Of these, 125 consecutive octogenarians were included and divided into two groups, according to the use of BITA grafts (101 subjects) or SITA grafts (24 subjects). Early and late outcomes were compared between groups.Results: The preoperative patient characteristics were similar between the two groups. Early outcomes were similar, including hospital death or deep sternal infection. The estimated 5-year survival rate was similar in the BITA and SITA groups (78% vs 62%, p = 0.269). Freedom from major adverse cardiac or cerebrovascular events was significantly higher in the BITA group than in the SITA group after 5 years (90% vs 75%, p = 0.032).Conclusions: Our results suggest that use of BITA grafts for CABG is feasible and beneficial in octogenarians, resulting in improved late outcomes without increased operative risk.