Seventeen patients with primary or metastatic malignancy in the liver were treated with 'two-route chemotherapy' (TRC). One course of this TRC consisted of hepatic artery infusion of cisplatin, 120 mg/m2, in combination with concurrent intravenous administration of sodium thiosulfate, its neutralizing agent, at a dose of 9.0 g/m2 by a rapid push, followed by 1.2 g/m2/h by continuous infusion for 6 h. Five of 11 (45%) hepatocellular carcinoma and two of six (33%) metastatic tumors achieved partial response. Although almost all patients experienced nausea or vomiting, severe side-effects, including nephrotoxicity, peripheral neuropathy or ototoxicity, were not encountered. Myelosuppression was observed in one patient after seven courses of this TRC. The results indicate that TRC may be relatively effective against hepatic malignancies in patients without severe toxicity.