We investigated whether strain rate imaging by echocardiography can quantify abnormal motion of interventricular septum (IVS) after coronary artery bypass grafting operation (CABG). Strain rate imaging was performed in 12 patients with angina pectoris treated by CABG; 12 patients with angina pectoris treated medically, with catheter intervention, or both (non-CABG); and 10 patients with previous anterior myocardial infarction. Peak systolic Doppler tissue velocity of mid-IVS was significantly lower in the CABG group than in the non-CABG group (2.15 ± 0.58 cm/s vs 3.37 ± 1.15 cm/s; P < .05). However, there was no significant difference in peak systolic strain (PSS) rate and PSS of mid-IVS between CABG and non-CABG groups. PSS rate and PSS of mid-IVS were significantly lower in the anterior myocardial infarction group than in the non-CABG group (−0.45 ± 0.25/s vs −1.22 ± 0.28/s and −5.8 ± 4.9% vs −17.2 ± 3.4%, respectively; P < .0001). Strain rate imaging can quantify accurate left ventricular function in cases of apparently reduced cardiac motion.