The aim of the study was the assessment of right ventricular (RV) structure and diastolic function in hypertensive subjects. The study group consisted of 44 patients with untreated, mild to moderate essential systemic hypertension. All the patients were in sinus rhythm, no symptoms of congestive heart failure, ischaemic or valvular heart disease and lung disorders were found. Twenty-six healthy subjects were the control group. M-mode echocardiographic measurements of the right ventricular wall (RVW) diastolic thickness, right ventricular outflow tract diameter (RVOTD), left ventricular (LV) structure and LV systolic function were performed. Pulsed Doppler echocardiography was used to measure peak early (TE) and peak atrial (TA) right ventricular diastolic filling velocities as well as velocity-time integrals (VTI-TE and VTI-TA). TE:TA and VTI-TE:VTI-TA ratios were calculated. Similar parameters of the left ventricular diastolic filling were recorded at the level of mitral annulus. Mean pulmonary artery pressure (MPAP) was measured non-invasively by the estimation of pulmonary artery systolic flows. We demonstrated in hypertensive patients significantly thicker RVW (3.94 vs 2.8 mm, P < 0.001) and increased LV mass. In the hypertensive, increased TA and VTI-TA and diminished TE:TA and VTI-TE:VTI-TA ratios were recorded, indicating the abnormalities of RV diastolic function. RV diastolic filling parameters correlated positively with corresponding parameters of LV filling. The results of our study demonstrate that impairment of LV diastolic function, the common finding in systemic hypertension, is associated with diastolic disturbances of the right ventricle. RVW thickening and hypertrophy of interventricular septum seem to be major factors influencing RV diastolic function.