Pulmonary artery wedge pressure (PAWP) measurement is invasive, associated with complications, contraindications and its high cost limits its use in clinical practice. We evaluated the use of dual-M-mode-echocardiography as a possible noninvasive alternative method in 20 patients for estimating the PAWP. The interval from the Q-wave of the electrocardiogram (ECG) to the mitral valve closure on the mitral valve M-mode-echocardiogram (Q-MVC), the interval between the aortic valve closure and mitral valve E point (AVC-E) on aortic and mitral valve M-mode-ECG respectively and the ratio of these intervals (Q-MVC/AVC-E) was correlated to the mean PAWP measured at catheterization. The mean PAWP correlated excellently with Q-MVC/AVC-E ratio [r = 0.89, p < 0.0001, y = 14.51 (Q-MVC/AVC-E) + 6.71]. The estimation of PAWP by a dual-M-mode-ECG offers a useful estimate of mean PAWP noninvasively.