Sickle cell disease is an important chronic inherited haemoglobin disorder, associated with recurrent vaso-occlusive and haemolytic crises and chronic tissue ischemia which may adversely affect any organ system including the cardiovascular system. Our objectives were to evaluate the cardiac performance in general with concentration on LV diastolic function and pulmonary artery pressure in young adult and adult Saudi patients originally from the Eastern province of Saudi Arabia. Forty-five patients with sickle disease were recruited for echocardiographic study while 45 controls, matched for age and sex, served as controls. Left and right ventricular dimensions and wall thicknesses of the LV, LV mass, LV mass index and LV contractility variables were obtained. Left atrial dimension and volume and pulmonary artery systolic pressure were also estimated. We evaluated also parameters of LV diastolic function including early and late atrio-ventricular flow velocities (E and A wave, respectively), E/A ratio, deceleration time (DT), A wave duration (A Dur.), and LV isovolumic relaxation time (IVRT). Other parameters of LV diastolic function including evaluation of Tissue Doppler Velocities, such as lateral annular e′ wave, a′ wave, e′/a′ ratio and E/e′ ratio were evaluated. There were increases in the LV dimensions, LV volumes, stroke volume, and LV mass indexes of the SCD patients. The preload was increased (LV diastolic volume) and afterload was decreased (low diastolic blood pressure). The LV ejection fraction was equivalent. However, there were evidences of LV diastolic dysfunction in 24%, and PH in 40% of the SCD patients. The mean left atrial volume was also increased in the SCD patients. Left ventricular diastolic dysfunction (Heart Failure with Preserved Ejection Fraction – HFPEF) and pulmonary hypertension may complicate cases of the Arab-Indian haplotype of sickle cell disease.