This study proposed a robot-assisted digital storytelling approach to reduce hospitalized children’s anxiety about intravenous injections and to improve their therapeutic communication and therapeutic engagement. In order to verify the effectiveness of the robot-assisted digital storytelling approach, a randomized controlled study was implemented. A total of 47 children from a regional hospital were randomly assigned to an experimental group (n = 21) and a control group (n = 26). The experimental group adopted the robot-assisted digital storytelling approach in health education for intravenous injections, while the control group received video-based health education. The study results indicated that the proposed robot-assisted digital storytelling approach not only reduced the children’s anxiety, but also had positive effects on children’s communication about intravenous injections, emotions during hospitalization, and therapeutic engagement. As a consequence, it is suggested that educators and researchers consider adopting robot-assisted digital storytelling to facilitate nursing clinical health education for children.