Diastolic dysfunction (DD) of the left ventricle (LV) is common. When severe it can result in heart failure with preserved ejection fraction (HFpEF). While right ventricular (RV) dilation and dysfunction are known to occur in HFpEF, effects of lesser degrees of DD on RV size and function have not been explored.A broad sample of 370 patients (age 60±15 years, 66% female) undergoing clinically indicated echocardiography had 3-dimensional imaging of the RV. A semi-automated program was used to measure RV volumes, ejection fraction, linear dimensions and longitudinal strain. LV diastolic function was graded per the 2025 ASE algorithm and RV measurements were compared across diastolic function groups.RV end-diastolic volume (RVEDV) and indexed RVEDV increased moving from normal diastolic function to grade 2/3 DD (p<0.0001). Regression analysis, controlling for age, sex, race, body surface area (BSA) and systolic pulmonary artery pressure (SPAP), found DD (diastolic dysfunction) remained significantly associated with RVEDV. RV basal and mid-cavity dimensions also increased across diastolic function groups (p = 0.0001) while RV longitudinal dimension was not associated with DD. RVEF showed a significant, graded decrease across diastolic function groups, independent of age, sex, race, BSA, and SPAP. Even comparing grade 1 DD with normal, there was a significant decrease in RVEF (p < 0.0003). Indexed left and right atrial volumes were similar when comparing normal with grade 1 DD; however, reservoir strain of each atrium was decreased with grade 1 DD.RVEDV and RVEF were significantly associated with LV diastolic function. Even moving from normal diastolic function to grade 1 DD was associated with a statistically significant drop in RVEF. Right and left atrial strains also decreased comparing grade 1 DD with normal diastolic function while indexed atrial volumes showed no significant change.