Background: The current study was designed to investigate the correlation between the left ventricular (LV) vortex flow pattern and LV apical thrombus formation in patients with acute anterior wall myocardial infarction (MI). Methods and Results: Fifty-seven patients with acute anterior wall MI were enrolled in this study. Eighteen patients with apical thrombus (thrombus group) and 39 patients without apical thrombus (non-thrombus group) underwent 2-dimensional contrast echocardiography (CE). Morphology and pulsatility parameters of the LV vortex were measured using Omega flow^® and compared between the 2 groups. In the thrombus group, the vortex was located more centrally and did not extend to the apex. In the thrombus group, quantitative vortex parameters of vortex depth (0.409±0.101 vs. 0.505±0.092, respectively; P=0.002) and relative strength (1.574±0.310 vs. 1.808±0.376, respectively, P=0.034) were significantly lower than the non-thrombus group. Following multivariate analysis, the vortex depth below 0.45 remained a significant independent parameter for formation of the LV apical thrombus (odds ratio 9.714, 95% confidence interval 1.674–56.381, P=0.011). Conclusions: These findings suggest that the location and pulsatility power of the LV vortex are strongly associated with the LV thrombus formation in patients with anterior MI. Therefore, LV vortex flow analysis using CE can be clinically useful for characterizing and quantifying the risk of LV apical thrombus in patients with anterior MI.  (Circ J 2012; 76: 2640–2646)