Objective: To determine the effect of aortic stiffness on right ventricular (RV) diastolic and systolic functions in individuals with left ventricular diastolic dysfunction (LVDD). Methodology: Patients aged above forty years with LVDD confirmed by transthoracic echocardiography were included in this study in Ain Shams University Hospitals from January 2015 to 2016.Systolic functions of the RV and LV were assessed by two-dimensional echocardiography and pulsed wave tissue Doppler echocardiography. The diastolic diameter was obtained at the peak of QRS complex of the single lead ECG recorded by the echo machine while the systolic diameter was obtained at the maximum anterior motion of the aorta. Aortic distensibility (AD), aortic strain (AS) and aortic stiffness index (ASI) were used as aortic elasticity parameters. Blood pressure was measured with a mercury sphygmomanometer. Results: A total of 300 consecutive patients were enrolled prospectively. This study showed that there were significant statistical differences between right ventricular diastolic function with all its states and aortic distensibility, aortic strain and aortic stiffness index. Various parameters reflecting right ventricular systolic and diastolic functions were independent predictors of AS, AD and ASI. Aortic parameters AS, AD and ASI were related to RV systolic function as the relation with TV S was 0.024, 0.002 and 0.010 respectively, also the relation with TAPSE was 0.027, 0.034 and 0.043 respectively. AS, AD and ASI were in addition related to RV diastolic function as seen with TV E/E' with p values 0.020, 0.020 & 0.000 respectively. RV DD grade was related to AS, AD & ASI with p values 0.010, 0.004 and 0.003 respectively. Conclusions: RV systolic and diastolic parameters are independent predictors of aortic parameters reflecting aortic stiffness. This relation needs further study to verify the relation of the aorta and right ventricle although they are not in anatomical continuity with each other.