Guided imagery is an established intervention in integrative oncology. This study was initiated to evaluate the impact of guided imagery on patients undergoing radiation therapy for breast cancer. Eligible patients receiving guided imagery sessions were monitored via biofeedback before and after each session. Monitored measures included blood pressure, respiration rate, pulse rate, and skin temperature. In addition, the EuroQoL Group's EQ-5D questionnaire was used for subjective assessment and patient feedback was collected at the end of radiation therapy through a satisfaction survey. Measured parameters revealed statistically significant improvement from baseline, with decreases noted in respiration rate and pulse rate as well as systolic and diastolic blood pressure. Skin temperature increased, indicating more peripheral capillary flow secondary to a decrease in the sympathetic response. Overall, 86% of participants described the guided imagery sessions as helpful, and 100% said they would recommend the intervention to others. The results of this study illustrate the positive impact of guided imagery as measured through subjective and objective parameters. Improving the overall care for patients with breast cancer supports the value of incorporating practices of integrative oncology into standard practice.