Twenty-nine (29) patients with recurrent head and neck carcinomas underwent (125)I seed permanent implantation under ultrasonography guidance and the feasibility and efficacy of (125)I seed implantation were assessed. The postplan evaluation showed that the actuarial D90 of (125)I seeds ranged from 90 to 160 Gy (median, 130 Gy). The activity of each (125)I seed ranged from 0.35 to 0.8 mCi (median, 0.6 mCi). The total number of sources implanted ranged from 3 to 61 (median, 22). The follow-up ranged from 3 to 40 months (median, 8 months). The 1-, 2-, and 3-year local control rates were 53.1%, 34.8%, and 17.4%, respectively, with a median local control of 16 months (95% confidence interval, 5.8-26.1). The 1-, 2-, and 3- year survival rates were 54.1%, 27.5%, and 27.5%, respectively (median, 13 months; 95% confidence interval, 6.0-19.9). Of the 25 patients, 5 (17.2%) died of local recurrence and 7 (24.1%) died of metastases; 2 patients showed recurrences at 3 and 8 months after seed implantation and subsequently died of pneumonia. One (1) patient died of heart disease. One (1) developed ulceration with tumor progression. Blood vessel damage and neuropathy were not observed. Percutaneous ultrasound-guided (125)I seed implantation is a feasible, safe salvage for patients with recurrent carcinomas of the head and neck.