In urban populations, worsening renal function (WRF) is well established in patients hospitalized with acute decompensated heart failure with preserved ejection fraction (HFpEF). However, the mechanisms for development of WRF in the setting of acute HF in HFpEF are unclear. In the present study, we sought to characterize conventional echocardiographic measures of right ventricular (RV) chamber size and function to determine whether RV dysfunction and/or adverse RV remodeling is related to WRF in patients with HFpEF. Our study included 104 adult patients with HFpEF (EF ≥ 55%) with technically adequate 2-dimensional echocardiograms performed during their hospitalization for acute decompensated HF to determine echocardiographic predictors of WRF, defined as a serum creatinine (Cr) increase of ≥ 0.3 mg/dl within 72 hours of hospitalization. Thirty-eight of the 104 patients (36%) developed WRF (mean Cr increase = 0.9 ± 0.1 mg/dl) during the hospitalization (mean age ± SD of 64 ± 12 years, 27 women [71%], 29 black [76%]). There were no significant differences in LV medial E/e' ratio and RV systolic pressure by WRF status or in linear dimensions of RV and right atrial size. RV fractional area change, a measure of RV function, however, was significantly decreased in HFpEF patients with WRF compared with the no WRF group (p = 0.003), whereas RV free wall thickness (p = 0.001) was increased. In conclusion, linear and volumetric measures of dimensions of right atrial and RV chamber size did not distinguish HFpEF patients with and without WRF. However, in HFpEF patients with WRF during acute HF hospitalization, there was a significant decrease in RV function and a significant increase in RV free wall thickness compared with matched patients with no WRF. These findings suggest that adverse RV remodeling and RV dysfunction occur in HFpEF patients with WRF.