It remains unclear whether the acute-phase ambulation program (AAP) improves the prognosis of heart failure (HF) patients. We examined the association between the initiation of AAP and the prognosis of patients with worsening HF. We enrolled 560 consecutive patients admitted due to worsening HF from March 2019 to April 2021. Our hospital introduced AAP in May 2020, but we did not perform AAP until April 2020. We retrospectively compared cardiac events within 180 days after discharge between patients admitted before April 2020 (conventional group) and after May 2020 (AAP group). Primary endpoints were all-cause mortality and readmission for worsening HF. The Kaplan-Meier survival curves showed a significantly lower event rate in the AAP group in HF readmission or the primary endpoint (p = 0.020 and p = 0.014). The occurrence of the primary endpoint was associated with age, history of HF, systolic blood pressure, medications including renin-angiotensin system inhibitors or angiotensin receptor blocker, hemoglobin, NT-proBNP, and AAP participation. After adjusting for these parameters and sex, participation in AAP was an independent factor associated with a reduced risk of primary endpoint occurrence (hazard ratio of 0.62 (0.41-0.95), p = 0.028). The AAP for patients with acute HF might lead to improved short-term prognosis and should be considered for implementation.