Background: Hospital length of stay (LOS) is a key determinant of heart failure hospitalization costs and performance of medical care quality. Right ventricular (RV) dysfunction predicted poor outcome in patients with acute heart failure (AHF). Aim: To study the effect of right ventricular function on length of hospital stay as a predictor in patients with acute heart failure. Methods: A prospective cohort study was conducted in CCUs in Zagazig University Hospital and Shark El Madina Hospital from September 2019 to February 2020, we included in this study 99 patients admitted with AHF. Clinical data and baseline RV function assessed by tricuspid annular plane systolic excursion (TAPSE) and S` velocity were collected. Clinical comorbidities including worsening renal function (WRF) were monitored during hospitalization. The primary outcome was hospital LOS. Results: There was significant correlation between WRF and poor outcome in patients with AHF including prolonged LOS. There is significant correlation between right ventricular systolic dysfunction identified by TAPSE