Carbon monoxide (CO) intoxication could cause significant cardiac injury. Although cardiac dysfunction after CO intoxication can be presented, the echocardiographic findings after CO intoxication are poorly defined. The purpose of this study was to evaluate the clinical patterns of left ventricular (LV) systolic dysfunction using echocardiography. A total of 132 CO-intoxicated patients were enrolled. Clinical, demographic and laboratory data and echocardiographic findings were analyzed. The LV dysfunction group (29 patients) showed higher lactate level (5.8 +/- 3.3 vs. 4.1 +/- 3.5 mmol/L, p = 0.024) and lower base excess (BE) (-8.2 +/- 6.0 vs. -4.8 +/- 4.7 mEq/L, p = 0.001) compared with normal LV function group. Among the LV dysfunction group, three different echocardiographic patterns were presented. Regional wall motion abnormality was presented in 14 patients. Apical ballooning, typical finding of stress-induced cardiomyopathy, was presented in eight patients. Global hypokinesia of LV was presented in seven patients. Laboratory findings indicating the severity of CO intoxication, such as lactate level, pH value, BE and aspartate aminotransferase, showed statistical significance according to the patterns of LV dysfunction (p = 0.033, 0.022, 0.02 and 0.006, respectively). Our results demonstrate that CO intoxication could induce various patterns of LV dysfunction. The patterns of LV dysfunction might affect subsequent clinical outcomes.