In the present study, we report two cases of splinting therapy where favorable results were obtained using splinting of two types, consisting of a first step of fixation at PIP joint extension position and DIP joint extension position, followed by a second step of further fixation at DIP joint extension position, followed thereafter by hand therapy on mallet finger. As the first splint flexes the PIP joint, and, further, as the DIP joint is taken as the hyperextension position, it is thought that the ruptured tendon ends sufficiently entwined more than with the conventional splint at the DIP joint extension position. The splinting therapy we used, with its two-type splinting, is thought to have enabled fixation and ROM acquisition that were in tandem with the tendon healing process. This treatment hints at the effectiveness of conservative therapy in the treatment of swan neck deformities and bony mallet finger.