Purpose <p>To investigate the effects of dynamic-static combined relaxation therapy on fatigue and sleep disorders in breast cancer patients undergoing chemotherapy.</p> Methods <p>A total of 114 patients receiving chemotherapy at Tangshan People’s Hospital (September 2023–June 2024) were randomly divided into three groups: control (routine nursing), experiment group 1 (static Benson relaxation), and experiment group 2 (dynamic yoga + static Benson relaxation). The intervention lasted 8&#xa0;weeks. Cancer-related fatigue and sleep disorders were assessed before and after intervention using the Revised Piper Fatigue Scale and the Pittsburgh Sleep Quality Index (PSQI).</p> Results <p>Prior to intervention, there were no significant differences in fatigue and sleep quality across groups (<i>P</i> &gt; 0.05). Post-intervention, both experiment groups showed significant improvements in fatigue and sleep quality compared to the control (<i>P</i> &lt; 0.001). Experiment group 2 showed greater reductions in behavior, body, and total fatigue scores compared to experiment group 1 (<i>P</i> &lt; 0.001). Sleep quality also improved significantly in both experiment groups, with experiment group 2 demonstrating superior outcomes in sleep quality, duration, daytime dysfunction, and total PSQI score (<i>P</i> &lt; 0.05).</p> Conclusion <p>The Benson relaxation technique and dynamic-static combined relaxation therapy are effective in reducing fatigue and improving sleep quality in breast cancer chemotherapy patients, with the dynamic-static combined relaxation therapy offering greater benefits.</p> Trial number <p>RMYY-LLKS-2024068.</p>