There is increasing interest in evaluating the use of nonpharmacologic interventions such as music to minimize potential adverse effects of anxiety-reducing medications. This study used a quasi-experimental design to evaluate the effects of a perioperative music intervention (provided continuously throughout the preoperative, intraoperative, and postoperative periods) on changes in mean arterial pressure (MAP), heart rate, anxiety, and pain in women with a diagnosis of breast cancer undergoing mastectomy. A total of 30 women were assigned randomly to a control group or to the music intervention group. Findings indicated that women in the intervention group had a greater decrease in MAP and anxiety with less pain from the preoperative period to the time of discharge from the recovery room compared with women in the control group. Music is a noninvasive and low-cost intervention that can be easily implemented in the perioperative setting, and these findings suggest that perioperative music can reduce MAP, anxiety, and pain among women undergoing mastectomy for breast cancer.