We recently reported that the early initiation of tolvaptan in congestive heart failure shortened the hospital stay and reduced the rate of in-hospital death. However, whether or not these results apply to elderly patients with congestive heart failure is unclear. We performed a sub-analysis of our previous study. Among the 102 patients in that study, we retrospectively analyzed the elderly patients >75 years of age treated with tolvaptan. First, we analyzed the efficacy of early tolvaptan use in these patients. We then compared the efficacy and the safety of all tolvaptan use between elderly and younger patients. There were no significant differences in the baseline clinical parameters between the early- and late-tolvaptan-use elderly patients, except for the serum blood nitrogen urea. However, the early use of tolvaptan was also associated with the earlier initiation of ambulatory cardiac rehabilitation, a shorter hospital stay, and a lower rate of in-hospital death in elderly congestive heart failure patients. Furthermore, there were no significant differences in the occurrence of worsening renal failure and hypernatremia. The early use of tolvaptan in elderly patients was also associated with a shorter hospital stay and reduced mortality. We also confirmed the safety of tolvaptan in elderly patients. It might, therefore, be beneficial to consider administering tolvaptan early in elderly patients with heart failure, just as in younger patients.