Background: The aim of the present study was to identify the clinical implications of newly developed akinesia in echocardiography after off-pump coronary artery bypass graft (CABG) surgery and its relationship with graft patency. Methods and Results: A total of 512 patients underwent off-pump CABG from January 2007 to November 2008. Two hundred and thirty-nine patients, whose echocardiography and multi-slice computed tomography data were available, were included in the study. Wall motion was subdivided into 16 segments and analyzed. Patients were separated into group A with newly developed akinesia (n=20), and group B without newly developed akinesia (n=219). Morbidity and early mortality, cardiac enzyme level, and graft patency were compared. The incidence of newly developed akinesia according to the anatomical territory was as follows: anterior, 5; lateral, 3; posterior, 7; and multiple territories, 5. Significant differences in preoperative ejection fraction were observed between the 2 groups (group A, 45.0 +/- 7%; group B, 58.0 +/- 12.2%, P<0.001). There was no statistical difference in the mean number of bypassed grafts and the complete revascularization rate. Complication and early mortality rates were insignificant between the 2 groups. There was little association between graft patency, cardiac enzyme level, and newly developed akinesia (P>0.05). Multivariate analysis showed that the preoperative ejection fraction was a risk factor for newly developed akinesia. Conclusions: The mechanism of development of akinesia after off-pump CABG might be attributable to intra-operative coronary malperfusion, which is probably due to cardiac manipulation rather than graft occlusion. (Circ J 2010; 74: 1564-1569)