Background: Pulse wave velocity, reflecting arterial stiffness, has been known to be elevated in patients with coronary artery disease (CAD) and congestive heart failure. However, the association between PWV and left ventricular (LV) diastolic function has not been fully evaluated. The aim of this study was to evaluate the relationship between aortic PWV and LV diastolic dysfunction in patients with CAD. Methods: We studied 234 patients (males, 65%; mean age, 62.0짹10.0) with CAD confirmed by coronary angiography (stenosis > 50% of the luminal diameter). Patients with symptoms or signs of congestive heart failure, LV ejection fraction < 50%, or B-type natriuretic peptide ��� 200 pg/ml were excluded. LV diastolic function was estimated by the ratio of the peak velocity of early rapid filling and that of atrial filling (E/A ratio), and myocardial diastolic velocity assessment (Em/Am, E/Em ratio) from basal septal LV wall measured by conventional and pulsed tissue Doppler imaging (TDI) echocardiography. LV diastolic dysfunction was defined as E/A < 0.75 or E/Em > 12. Aortic stiffness was evaluated by non-invasive carotid-femoral PWV measurement using applanation tonometry method. Results: Aortic PWV correlated positively with age, systolic blood pressure, pulse pressure, E/Em, BNP and negatively with E/A, Em/Am. Multiple regression analysis demonstrated that age (p < 0.001) and E/A (p = 0.042) were independently related to aortic PWV. The receiver operator characteristic (ROC) curve showed that an aortic PWV of 7.87 m/s was indicated to discriminate LV diastolic dysfunction (sensitivity = 67%, specificity = 59%). Conclusion: The present study demonstrated that increased aortic PWV was associated with LV diastolic dysfunction in patients with CAD. Aortic stiffness measured by PWV may be a possible predictive marker for LV diastolic dysfunction.