Abstract Background It is a well-known fact that for patients with decompensated congestive heart failure (CHF) who require hospitalization, starting cardiac rehabilitation (CR) early after hospitalization has a positive impact on their clinical course. To maintain their activity and nutritional status through the early mobilization by efficient medical care, we have introduced our own clinical pathway(PATH) for CHF since August 2015. In PATH, the initiation of CR early after admission was stipulated. With PATH introduction, starting time of CR was significantly earlier and the average hospitalization period for CHF cases was also significantly reduced. However, there are still some cases applied PATH who are unable to start CR early after admission for various reasons. Purpose We examined whether the clinical course after admission differs depending on the timing of CR initiation even in CHF cases applied PATH. Methods We enrolled 933 patients admitted with CHF for the first time from August 2015 to July 2023, applied PATH, started physical therapy (PT) as CR, and discharged alive. We divided them into two groups based on when they started PT, Early-group (649 cases: Starting time is within the 3rd hospital day) and the Late-group (284 cases: Starting time is after the 4th hospital day). And we investigated patient background, clinical data at admission, and clinical course after admission for all cases, and examined the differences in each item between the two groups. Results There were no differences in patient characteristics or clinical data at admission between the two groups (Table 1). On the other hand, although there was no difference in the performance rate of each acute treatment between the two groups, the performance duration of each treatment in cases introduced was significantly shorter in Early-group. Furthermore, the average meal (side dish) intake rate on the 2nd to 4th hospital days after admission was significantly higher in Early-group, and the average length of hospitalization was significantly shorter in the Early-group (Figure 1). Conclusions For 8 years, we have strived to begin cardiac rehabilitation interventions early after hospitalization with introduction of our own clinical pathway. However, we found that even with the introduction of the clinical pathway, cardiac rehabilitation was started on or after the 4th hospital day in 30% of all cases. And we found that in these cases, each treatment during the acute phase was prolonged, nutritional intake was inadequate, and the length of hospitalization tended to be prolonged. The delay in initiation of rehabilitation was thought to be related to factors such as the timing of hospitalization (admission on holidays or public holidays) or the location of hospital management (ICU management in severe cases). It seemed necessary to create a system that would allow cardiac rehabilitation to be started flexibly even in such situations.Table1Figure 1