The effect of intra-arterial infusion chemotherapy with adriamycin (ADM), with special references to its pharmacokinetic behavior and also the tissue concentrations, was studied in 8 patients with locally advanced breast cancer. A high clinical response rate (CR + PR) of 70.0% was obtained by the treatment, and also remarkable degenerative changes of tumor cells were histologically noted in 5 out of 9 surgical specimens (55.6%). Side effects such as alopecia (100%), leukopenia (87.5%) and stomatitis (85.5%) were frequently observed, but none of them delayed the following mastectomy. Pharmacokinetic studies of intra-arterial administration of ADM showed a low serum concentration and its rapid clearance from serum. ADM also seemed to have a great affinity to the regional lymph nodes (1.21 micrograms/g tissue), compared to cancer (0.61 micrograms/g) and normal breast tissues (0.51 micrograms/g). These results suggested that intra-arterial infusion chemotherapy with ADM might be applicable not only for the preoperative treatment of locally advanced breast cancer, but also for the control of lymph node metastasis.