To improve the treatment results for locally advanced head and neck cancer, chemoradiation therapy by radiotherapy, systemic chemotherapy with 5-fluorouracil (5FU) and nedaplatin (NDP), and intra-arterial therapy using carboplatin (CBDCA) was performed. Thirty-two patients were entered into the study between July 1997 and August 2002. According to the TNM staging (1997), 14 patients had stage III lesions, and 19 patients had stage IV (M0) lesions. Alternating chemoradiotherapy was performed by the following regimen. Initially, systemic chemotherapy was administered, followed by 4 weeks of radiotherapy (36Gy/20 fractions; wide field irradiation) starting 2 days after chemotherapy, a second course of systemic chemotherapy 2 days after radiotherapy, and a second course of a reduced field radiotherapy (30Gy/15 fractions) 2 days after chemotherapy. Arterial injection therapy was administered in the latter half of radiotherapy after the end of the second course of systemic chemotherapy. For systemic chemotherapy, 5FU at 3500mg/m(2)/120h was intravenously administered for 5 days (Days 1-5), and NDP at 120mg/m(2)/6h was administered on Day 6. An intra-arterial agent using CBDCA was continuously infused by a portable electrical pump for 4 (to 6) weeks. The total dose of CBDCA was AUC 6 as established by Calvert's formula. The 5-year local control rate was 59%. The 5-year overall survival rate was 51%. There were no clinically significant adverse effects. Chemoradiation therapy by radiotherapy, systemic chemotherapy, and intra-arterial chemotherapy for locally advanced head and neck cancer may be useful for improving treatment results.