Background: Metabolic syndrome (MS) predisposes to left ventricular dysfunction and heart failure, however, alterations in left atrial (LA) function in MS are unknown. Objectives: We aimed to use strain/strain rate (SR) imaging to investigate the effect of MS on LA function. Subjects and Methods: This prospective case control study included a total of 100 subjects divided in to 75 metabolic syndrome (MS) patients referred to Al-Azhar university hospital outpatient clinic for evaluation and treatment of hypertension and/or diabetes mellitus and 25 age and sex matched apparently healthy volunteers as a control group. All subjects underwent conventional echocardiographic examination and assessment of LA function by speckle tracking. Partial correlation and multiple stepwise regression analyses were used to determine the risk factors for impaired LA function. Results: Compared with the controls, the MS patients showed significantly lower levels of mean strain, mean peak systolic SR and mean peak early diastolic SR (P<0.05 for all), with no difference in the mean peak late diastolic SR. Central obesity, hypertension, dyslipidemia and uncontrolled diabetes were independent risk factors for impaired LA function. Conclusion: SR imaging is reliable in assessing LA function in MS patients.