Objective: Metabolic syndrome (MS) is a condition, which is recognized as raising the risk of cardiovascular disease. The aim of our study is to estimate the left ventricular functions by atrioventricular plane displacement (AVPD), myocardial performance index (MPI) and conventional methods in patients with MS who were diagnosed according to NCEP (ATP III) criteria. Methods: Fifty-three female patients with MS (mean age 53.1±6.9 years) and 30 healthy female subjects (mean age 52.8±6.3 years, p>0.05) underwent complete echocardiographic assessment. All of the subjects had no heart and pulmonary diseases. The systolic mitral AVPD was recorded at 4 sites (septal, lateral, anterior, and posterior) by M-mode echocardiography and left ventricle ejection fraction (LVEF) was calculated from the AVPD-mean (EF-AVPD). The LVEF was also established by biplane Simpson’s (EF-2D) and Teichholz’s methods (EF-T). Left ventricular MPI was calculated as (isovolumic contraction time + isovolumic relaxation time) / aortic ejection time by Doppler echocardiography. Results: Patients with MS showed mild left ventricular diastolic dysfunction (DD) in comparison to healthy subjects. The EF-2D and EF-T in patients with MS and healthy subjects were not different significantly and were within normal limits. Patients with MS showed LV global dysfunctions compared to healthy subjects (MPI: 0.56±0.12 and 0.46±0.11 respectively, p<0.01). Both the septal, anterior, lateral and posterior part of the atrioventricular plane values and also AVPD-mean during systole were statistically lower in patients with MS (12.85±1.76 mm) as compared with controls (14.65±2.19 mm, p<0.05). EF-AVPD in patients with MS was statistically lower (65.58 ±11.95%) as compared with healthy subjects (74.45±11.07 %, p<0.01). Conclusion: Female patients with MS had both left ventricular DD and a global dysfunction with an increased MPI. The EF-2D and EF-T were not different significantly between patients and controls, but patients with MS had a relatively reduced EF-AVPD. The AVPD method may indicate a systolic dysfunction with a relatively lower AVPD-mean and relatively lower EF-AVPD. The presence of global dysfunction in patients with MS may lead to heart failure