Along with coronary evaluation, 64-slice multidetector computed tomography (MDCT) permits comprehensive assessment of left ventricular (LV) anatomy and function; however, how it compares with 2-dimensional transthoracic echocardiography (TTE) in patients with heart failure (HF) is not known. In this study, we compared 25 patients with ejection fractions of <45% who underwent TTE and MDCT. The global ejection fraction by TTE versus MDCT was 36 ± 8% versus 38 ± 12% (r = 0.67, p = NS). The mean LV end-diastolic and end-systolic diameters by TTE and MDCT were 56 ± 8 and 46 ± 9 mm and 58 ± 12 and 47 ± 11 mm, respectively (r = 0.71 and 0.77, respectively, both p >0.20). The mean lateral and septal wall thicknesses by TTE and MDCT were 10 ± 1.4 and 11 ± 1.5 mm and 10 ± 1.3 and 10 ± 1.4 mm (r = 0.77 and 0.76, respectively, both p >0.20). The mean LV end-diastolic and end-systolic volumes and stroke volume by TTE and MDCT were 123 ± 45, 78 ± 31, and 44 ± 21 ml and 140 ± 58, 92 ± 43, and 48 ± 24 ml, respectively (r = 0.62, 0.67, and 0.60, respectively, all p >0.20). The regional wall motion assessment correlation was good between the 2 modalities (κ = 0.61). The interobserver correlation between the 2 MDCT readers ranged from good (r = 0.72 for LV end-diastolic volume) to excellent (r = 0.84 for septal wall thickness). In conclusion, MDCT provides comparable results to TTE for LV structure and functional assessment among patients with HF.