Review of the current state of knowledge about Doppler diagnosis of pulmonary hypertension is presented. The authors compare the findings of numerous studies with their own data and analyse the causes of discrepancies and controversies that have remained to date. Doppler estimation of mean pulmonary artery pressure (PAP) using acceleration time (ACT) measurement in the right ventricular outflow tract or main pulmonary artery has been shown to correlate closely with simultaneously measured values of PAP both at rest and during exercise (r = -0.92 and -0.94, respectively). ACT values show sufficient sensitivity for the detection of pulmonary hypertension (89%), at maximum (100%) specificity. However, Doppler values not obtained simultaneously do not necessarily correlate with PAP in view of rapid physiological variations of PAP. For everyday diagnostic practice in cardiology, prediction based upon mere qualitative estimation of the type of velocity curve seems sufficient. Doppler diagnosis of pulmonary hypertension, little demanding on both technical skills and equipment, is gaining a priority status among the non-invasive methods available.