[Purpose, Case, and Methods] A female bottlenose dolphin (Tursiops truncatus) in captivity developed necrosis of the tail flukes. Although the diseased site healed after surgical resection, the loss of approximately 75% of the tail greatly affected her swimming performance. To restore swimming ability, we developed artificial tail flukes as a prosthetic swimming aid and provided physical therapy that included swimming training from postoperative day 1 to day 1427. [Results] The prosthetic enabled the dolphin to recover swimming ability almost to the level prior to disease onset, but even acquire applied movement, and reestablish social relationships, thus greatly improving the animal’s quality of life. [Conclusion] The results clearly demonstrate that, as in postoperative rehabilitation in humans, the use of prosthetic devices in physical therapy can be beneficial for marine animals such as dolphins.