Transmitral E wave velocity was reported to be positively related to left ventricular (LV) filling pressure and negatively related to LV relaxation constant, and isovolumic relaxation flow propagation velocity (IRFPV) was proven recently to be negatively related to LV relaxation constant and independent of preload alterations. Therefore, the combination index, E/IRFPV, may eliminate the influence of LV relaxation and bring the LV filling pressure into focus. However, it is unknown whether E/IRFPV is a useful index in prediction of LV filling pressure. The aim of this study is to evaluate the correlation between E/IRFPV and LV end-diastolic pressure (LVEDP). Forty-three patients with suspected coronary artery disease who underwent a Doppler echocardiographic study and cardiac catheterization were included. LVEDP was determined by a micromanometer-tipped catheter. In a univariate analysis, LVEDP had a positive correlation with left atrial dimension, LV end-diastolic dimension, LV end-systolic dimension, the ratio of E to E wave propagation velocity (EPV) (r = 0.408, p = 0.007), the ratio of E to early diastolic mitral annular velocity (Ea) (r = 0.439, p = 0.003) and E/IRFPV (r = 0.686, p < 0.001). It had a negative correlation with diastolic blood pressure, E wave deceleration time, LV ejection fraction, EPV, Ea and IRFPV. After stepwise multiple linear regression analysis, only the E/IRFPV was the independent predictor of LVEDP (beta = 0.667, p < 0.001). In conclusion, E/IRFPV is a useful parameter in prediction of LVEDP.