We sought the impact of recent recommendations on observer concordance on interpretation of diastolic stage and assessment of filling pressure.Worsening stages of diastolic dysfunction are associated with worsening outcome. However, the echocardiographic classification of diastolic function is complex, and parameters may be discordant. The interobserver agreement of diastolic assessment is undefined.A complete diastolic evaluation (transmitral flow, left atrial volume, tissue Doppler, pulmonary venous flow, mitral flow propagation, and left ventricular images) was obtained in 20 patients and interpreted by 14 experts in 8 countries (280 case reads). Each investigator was asked to interpret diastolic class and left ventricular filling pressure. Brain natriuretic peptide level was drawn on the same day of the echocardiogram to corroborate filling pressures obtained by the echocardiogram. Concordance was assessed as kappa, and accuracy was compared with specific application of the recommendations by 2 investigators.For recognition of raised filling pressure, the sensitivity and specificity of readers for raised filling pressure defined by the reference read were 66 ± 37% and 88 ± 26%, respectively. Complete agreement among all readers was obtained in 10 of 20 cases. Diagnosis of normal and categories of abnormal filling was correct in 71% to 95%, with the lowest values obtained for normal and pseudonormal filling. There was no difference between U.S. and international readers. Not all patients in each diastolic stage showed all of the changes that are typical of that stage, and variations appeared to be attributable to differences in weighting of conflicting observations. Overall, kappa values for filling pressure and diastolic class were 0.71 (range 0.60 to 0.80) and 0.68 (range 0.54 to 0.86).Correct results for estimation of filling pressure were obtained by a high proportion of readers. Classification of diastolic stages continues to be variable and might be addressed by provision of a uniform hierarchy of observations.