Endomyocardial fibrosis is manifested mainly by diastolic heart failure. However, diastolic function has not been well characterized in this disease. The aim of this study was to characterize left ventricular (LV) diastolic function in endomyocardial fibrosis (EMF) by echocardiography. Eighteen patients with LV EMF and 18 healthy subjects were studied. Cardiac volumes and ejection fraction were assessed by Simpson's method. Pulsed-wave Doppler was used to obtain mitral and pulmonary venous flow velocities and grade diastolic function. Pulsed-wave tissue Doppler imaging velocities along the septal side of mitral annulus, flow propagation velocity (Vp) of the early diastolic mitral inflow, and myocardial performance index were obtained. According to this grading method, four patients with normal diastolic function, five with impaired relaxation, five with pseudonormal, and four with a restrictive pattern were found. A positive correlation of these diastolic function grades and NYHA functional class was found (r = 0.66, P = 0.003). By "stepwise" logistic regression the best index that discriminated EMF patients from controls was Vp. The probability of occurrence of EMF = exp(7.9288 - 0.1366 Vp)/1 + exp(7.9288 - 0.1366 Vp). A wide range of diastolic function grades is found in patients with EMF and these correlated with functional class. Delayed myocardium relaxation, as reflected by altered Vp, was a frequent finding, making Vp the most useful index to discriminate EMF patients.