The treatment of chronic arm lymphedema following axillary dissection for breast cancer is still a therapeutic challenge. To examine other treatment options, we undertook a pilot study on the efficacy of ultrasound therapy (UST) in management of these patients. Fifty patients with post-surgical arm lymphedema and without regional irradiation underwent ultrasound treatment (2 cycles at 4 month intervals) and the results were compared up to 1 year with 100 other patients treated by standardized mechanical pressure therapy (MPT) using a pneumatic pump. In this report we evaluate 96 patients who have been followed after 1 year, 31 of whom belong to UST group and 65 to the MPT group. UST did not show a statistically significant difference in whole arm reduction of lymphedema although there was initially a greater reduction in size after the first 4 months of treatment. The addition of an elastic sleeve did not improve lymphedema in either group. Advantages of UST were an overall shorter length of treatment, a tendency to greater softening of the arm, patient satisfaction by avoidance of an uncomfortable and constrictive device and better relief of osteomyofascial pain, greater scapulohumeral motion, and less intercostobrachial pain-dysesthesia.