Anthracyclines are potent antineoplastic agents associated with cardiotoxicity, which may lead to congestive heart failure, causing impairment of autonomic cardiovascular function as assessed by heart rate variability (HRV). This decreases survival rates. This study aimed to determine whether music therapy intervention improves autonomic function in anthracycline-treated breast cancer patients, and if so, whether such improvements persist after cessation of the intervention. Participants were 12 women with breast cancer who had undergone mastectomy or breast-conserving treatment and adjuvant chemotherapy; they attended 8 weekly music therapy sessions, each lasting 2 hours. Electrocardiogram traces (5 minutes) for HRV analysis were recorded 4 times: prior to the first music session, T1; after the fourth music session, T2; after the eighth music session, T3; and 4 weeks after the completion of music therapy, T4. HRV parameters were subjected to a nonparametric Friedman test on the differences between T1 and T2, T3, and T4. The standard deviation of normal intervals and the total power of HRV parameters, related to global autonomic function, were significantly higher at T3 than at T1. The root-mean-square differences of successive normal R-R intervals and high-frequency (HF) HRV parameters, related to parasympathetic activity, were significantly increased, but no change was seen in the LF/HF ratio of HRV parameters (which is related to sympathetic activity) during the music therapy. Global autonomic function and parasympathetic activity had not changed significantly at T4 relative to T1. The authors provide preliminary evidence of the benefits of music therapy for anthracycline-treated breast cancer survivors.