Background: Bone marrow transplant units are stressful work environments with high staff burnout, anxiety, and turnover. Nursing care of blood and marrow transplantation patients is complicated. Studies directly compare the clinical efficacy of different Tai Chi exercises in treating anxiety and stress symptoms despite the growing body of evidence supporting the beneficial effects of Tai Chi in reducing these symptoms. Therefore, the current study aimed to determine the effectiveness of Tai Chi exercise application on nurses' stress and anxiety when caring for patients with bone marrow transplantation. Research design: A quasi-experimental research design was used to fulfill this study using a pre-test and post-test one-group design. Setting: The study was conducted at an Oncology institution affiliated to Sohag University, Egypt. Subject: A convenient sample that included (50) nurses was selected by using a Nonprobability Purposive sampling technique. Tools of data collection: Three tools were used; Tool (I): Personal data of the nurses, Tool II: Perceived Stress Scale-10 (PSS-10), and Tool III: The State-Trait Anxiety Inventory. Results: A statistically significant difference was found between stress mean scores and anxiety at (P=0.001) pre and post-Tai Chi exercise application. Also, a substantial reduction in pre- and post-Tai Chi exercise application between the groups was reported regarding stress and anxiety levels. Conclusion: The application of tai chi has resulted in a significant decrease in mean post-test stress and anxiety among nurses caring for patients with bone marrow transplantation.  Recommendations: Provide a training program for nurses caring for patients with bone marrow transplantation about the importance of the Tai Chi exercise application to be able to use them as a part of routine care with patients.